A few ideas come to mind, however it depends on whether the POD is pre-war or post-war as well as pre-BMC or post-BMC as there are almost countless options for BMC to thrive and butterfly away its merger with Leyland Motors to create British Leyland.
Post-War options for BMC include:
- Austin would be otherwise unchanged apart from initially producing a post-war Austin A35 derived from a SWB Austin A40 Devon with 1-litre version of the 1.2-litre A40 engine, which Nissan reputedly produced later on in the late-1950s as part of its license agreement with Austin as the Nissan C (aka Stone) engine. It could also maintain relations with Nissan whether by adding more strings to their license agreement or further collaborations down the road (with scope for ATL BMC to ally/acquire Nissan in place of Renault along with possibly BMW).
Austin would also produce an earlier 2-litre+ inline-6 version of the 1.2-litre A40 engine that post-BMC would eventually become an ATL early 2.0-3-litre B-Series "Blue Streak" 6-cylinder. The B-Series under BMC would later be enlarged to 106 hp 1998cc as well as be converted to 112-115 hp B-OHC (in 2-litre form) for non-MG models from the early-1960s before the production tooling is completely worn out.
- Lord Nuffield takes a step back and not sabotage post-war modernization / investment of the company nor lets his feelings for the Morris Minor to get in the way of its success as a viable rival for the Volkswagen Beetle, yet still plots with Leonard Lord on merging the companies into BMC albeit on more equal terms compared to OTL.
ATL changes include rationalized engines down to a 33-85 hp 918-1600cc version of the Wolseley Eight OHV engine that would remain in production post-BMC till the early/mid-1960s, along with an earlier post-war 47-200+ hp 1500-3250cc+ (to 4-litre) 4/6-cylinder C-Series OHV (later OHC / Twin-Cam) from the outset.
Upon the formation of BMC. They would to rationalize their marque portfolio down to 4 (Austin, Morris, MG and Vanden Plas) as well as would put their under-utilized Research Department towards taking the cost out of the Mini and other FWD models from the outset instead of Harriman telling the head of the Research Department to speak to Issigonis about his proposal in late-1962 (that went nowhere).
Before that would have Joe Edwards succeed Leonard Lord in place of George Harriman, meanwhile Gerald Palmer would be kept a bit longer at BMC to properly-develop the B-Series Twin-Cam, along with produce the C-Series Twin-Cam and play a productive role in developing BMC's new generation of conventional RWD cars for the 1960s while Alec Issigonis sticks to his trio of FWD cars.
After thoroughly developing their 5 (later 4) engines from the 918-1600cc Wolseley Eight OHV, 719-1275cc A-Series, 1600-3000cc 4/6-cylinder B-Series , 1500-3250 (possibly 4-litre) 4/6-cylinder C-Series and 2000-4000cc 4/6-cylinder D-Series engines. The car production engines would be rationalized down during the 1960s as follows:
- A-Series - Essentially updated to early A+ spec from the mid/late-1960s, it plays a similar role for BMC as the older Renault Billancourt did for Renault once the newer C-Type engine appeared as a more economy focused long-stroke OHV engine that still shares much with the larger A-Plus for both to be considered Half-Relations or more and spawns smaller capacity variants, thereby allowing the Mini to fit into even lower tax brackets in certain markets as well as allow it to be exempt from various emissions standards for cars with engines below 49-50 cubic inches / 803-819cc when they appear in the late-1960s. It would later be indirectly replaced by 3-cylinder versions of the larger A-Plus before being directly replaced in the mid/late-1980s by a rough composite of the Nissan CG / Nissan CR and Renault D-Type engines.
- A-Plus - Replacing the Wolseley Eight OHV and indirectly the A-Series. Despite carrying over the A+ name, it is essentially a slightly upscaled 850-1600cc A-Series half-relation that roughly weighs the same as the existing A-Series and is still able to easily slot into the engine bay of a Mini. It is an early composite of the A+, South African A-Series and A-OHC engines where the lower-displacement versions are short-stroke units, whilst featuring elements of the distantly related Nissan A OHV / Nissan E OHC / Nissan MA SOHC / Nissan GA (SOHC / DOHC) as well as similarly sized Renault C-Type and E-Type (plus related Ford CHT unit). It would feature limited-run 1.6 Twin-Cam versions to take on the Lotus-Ford Twin-Cam as well as 3-cylinder variants to eventually replace the smaller A-Series and diesel variants (including Daihatsu C engine inspired 3-cylinder diesel), with its distantly related successor resembling a late-1980s composite of the Renault K-Type and Nissan QG engines (with elements of the Suzuki G engine).
- E-Series - Replacing the B-Series, C-Series and D-Series engines. It is essentially a properly-developed version (with involvement from the likes of Daniel Richmond of Downton Engineering, etc) that resembles the Volkswagen EA827 yet features a more compact block like the later related S-Series engine (thereby allowing BMC's models to feature lower-bonnet lines akin to the OTL Austin Montego - as opposed to the Austin Maestro whose rush to production did not allow for it to be designed around the S-Series engine), displacements for the 4/6-cylinder engine would range from 1300-3000cc instead of 1500-2200/2600cc as in OTL as well as diesel/turbodiesel (plus ethanol, LPG / CNG) variants. Its successor would follow the EA827-derived Volkswagen EA113 as well as the O-Series derived Project Storm / Td5 in being a far more modular design by spawning 4/5/6-cylinder and V8+ engines.
ATL BMC Cars:
The late-50s Farina B/C RWD cars would largely be derived from Morris Oxford III / Isis mechanicals instead of the mk1 Austin Cambridge A55 and Austin Westminster A95/A105, its styling featuring more elements from the Peugeot 404 and more subtle or zero tailfins. MG would utilize similar components though feature an independent rear suspension whether via Coil Springs with Watts linkage or properly-designed Frontline-style Panhard Rod for its own range of RWD cars as was originally intended for the MGB.
The above along with the Minor and A40 Farina would be replaced by a Morris-only conventional three-box RWD family trio of cars akin to an early-1960s Morris Marina / Ital.
The new RWD Minor would conceptually resemble a Vauxhall Viva HA (which Gerald Palmer was involved with at Vauxhall) and Nissan Sunny B10/B110/B210 as well as precede the mk1 Ford Escort featuring 1000-1300cc+ engines, the medium-sized RWD Marina model would be a mk1/mk2 Ford Cortina rival with 1100-2000cc engines, while the largest model would be akin to the Opel Commodore (and Ford Corsair) with 2400-3000cc+ engines. Their role is to retain their existing clientele of conservative customers who would be suspicious of BMC's FWD cars and prevent them from going to rivals still making conventional front-engined RWD cars, at least until the FWD layout has proven itself by the early-1970s onwards for Morris to eventually switch over to FWD with conventional suspension and gearbox.
The Austin-only FWD cars would feature 3/5-door hatchbacks from the outset, apart from more luxurious three-box saloon Vanden Plas variants and a possible two-box saloon entry-level 2/4-door version of the Mini with sub-803cc engines. The three-box saloons would resemble the MG ADO34 and Vanden Plas 1800 prototype from the rear-end. The ATL 1100/1300 and 1800/2000 meanwhile would feature conventional end-on instead of in-sump gearboxes from the beginning, followed later by an ATL version of the Mini ADO20 (the latter being a composite of Project Ant, Clubman hatchback and Minki-II with Rover R6-like Hydragas suspension and 12-inch wheels). The Cooper name would be used to denote sporting non-MG versions of BMC's cars.
BMC would acquire Rover instead of Jaguar in the mid-1960s, which depending on whether the ATL revised C-Series meets its weight reduction targets (and features proper development) could mean the Rover V8 finds its way into the ATL MGC from the outset. In Rover's case the ideal before joining BMC would have been to also acquire the rights to build the Buick V6 (along with AMC), though can see Rover replacing the P6 OHC 4-cylinder and Rover V8 with a common family of 4/5/6-cylinder and V8 engines derived from the unbuilt DOHC 16-valve fuel-injected P10 engine before it is eventually replaced by BMC's own modular engine family.
The OTL aerodynamic styling themes found on the MG ADO21 (later the Triumph TR7/TR8), Pininfarina 1100/1800 and Ferrari Daytona-inspired Rover SD1 would have been better off utilized exclusively by MG from an ATL EX234 prototype and beyond (with the Rover P9 possibly becoming a flagship MG supercar). Austin would in turn benefit from Peugeot-like Pininfarina styling and Morris from in-house styling, while Rover would look to the successful Range Rover on ideas for a more conservative styling approach for its higher-end P10 (ATL SD1) and P8 saloon cars.
The Mini-sized 1100/1300-derived Suzuki Jinmy rivalling Austin Ant prototype would be repurposed as a junior Land Rover model. The ATL 1100/1300 platform would also form the basis of British equivalents to the Autobianchi Primula-based Fiat 238 and Fiat 128-based Fiat X1/9 sportscar (akin to Healey WAEC prototype), along with possibly a stop-gap supermini akin to the Fiat 128-based Fiat 127 as well as the Simca 1100-based Matra Rancho. The 1800/2200 meanwhile would form the basis of a FWD Austin commercial vehicle (essentially a production version of the CV300), while the early-1960s Marina/Ital family would form the basis of an early-1960s Morris Sherpa.
Both MG and Rover would be twinned to some extent under BMC, though the latter would be more upmarket with conventional styling and sophisticated suspension while MG would feature sporting aerodynamic styling, all-independent suspension and reliable Twin-Cam engines akin to Alfa Romeo.
The Mini and 1100/1300 would be replaced by ATL ADO20 and ADO22 from the late-1960s, the ATL 1800/2200 meanwhile would be replaced by an ATL X6 prior to being succeeded by ATL Austin Princess with all featuring end-on gearboxes and Hydragas suspension. Some form of Austin Allegro does still reach the prototype stage in ATL, however it is instead used as a starting point for a common family of mid/late-1970s FWD cars ranging from a large supermini and early-Maestro/Montego to a Princess successor. The Austin versions would feature Peugeot-like Pininfarina styling and Hydragas suspension, while the Morris versions would feature in-house styling and conventional suspension.
Some form of Metro does still appear in ATL below the early Maestro-derived large supermini, though it is commonized with Mini ADO20 and is more like the Rover Metro R6 in featuring end-on gearbox as well as Hydragas suspension in Austin form, while Morris versions feature mk1/mk2 Volkswagen Polo-like conventional suspension and differing styling. It is possible the Mini ADO20 reverts to more retro-styling by the early/mid-1980s as a unique marque in its own right below the Metro. Its platform would evolve along similar lines to the Ford B platform that underpinned the (1st to 4th gen) Ford Fiesta from 1976 to 2003 along with the Ford Ka, Ford Puma, Ford Ikon and Ford Bantam / Ford Courier that depending on the model remained in production until 2011.
By the mid/late-1980s the FWD cars are replaced by a modular version of the Austin AR6 platform ranging from a Metro to a Montego/Princess replacement.
On the MG sportscar front. Envision an ATL version of the EX234 platform going on to underpin various MG sportscars for a number of decades akin to the Nissan Z-Car (from S30 and S130 to 31Z), Nissan S platform and Mazda RX-7 (from FB to FC), curiously the latter would also form the basis of the mk1/mk2 Mazda MX-5 until 2005. Another interesting thing would be the fact the OTL Nissan Silvia S10 that first used the S platform was derived from the coupe version of the Nissan Sunny B210.
International post-war PODs that would benefit BMC:
- A right-leaning India headed by Sardar Patel / Rajaji with no License Raj would provide opportunities for BMC to establish a larger presence in the country.
- Following Volkswagen's example by establishing a presence in places like Brazil and Mexico.
- The UK joins the EEC in 1963 partly a result of Charles de Gaulle (who prevented the UK joining in OTL) being assassinated in 1961 when his car was hit by a bomb near the village of Crancey in the Pont-sur-Seine district (with Gaston Monnerville taking over as acting president prior to becoming a 2-term president).
- BMC would integrate its European operations in Spain (e.g. Authi, Santana), Italy (e.g. Innocenti / Lambretta) as well as its Latin American branches (including Siam Di Tella).