Add automatic gearbox, more power, a bigger boot and understand that Americans at least have no use for legroom. I never knew that you could get so little passenger space into so much car until I took a taxi in Boston. I would have been better off in the open boot (pardon me, trunk) unless it rained. Definitely needs winterising too and with air conditioning. Best sold direct from a set of dedicated city based sales and servicing outlets (separate from the Austin dealerships) so that the profit comes from aftermarket work and lets you sell them cheap at cost price. One presumes reliability based upon UK experience. Later it will need power steering and disk brakes. A pick up/utility/van version has more sales potential than a private saloon and will help keep up the numbers to make best use of the FX4 dedicated sales servicing shops. Locally built engines will help and may feed back into UK production.
The FX4 and Standard Vanguard were about the only British cars able to survive on loose surface roads.