I guess we ought to look at this comprehensively.
What factors have been involved in successful/long-lived resistance or terror groups?
1) reasonably sympathetic population: I think we can see this at work (to varying extents) in the IRA, various Pelestinian groups, the Viet Cong, and the post-WW2 Baltic resistance movements.
There were undoubtedly Nazi sympathizers after WW2 (there still are, ugh), but the great majority of Germans seem to have been quite disenchanted in the postwar period. So I'm not seeing much popular support.
2) external financing/training/equipment: definitely at work with the Palestinians, Vietnam Cong, the Baltic anti-Soviets, and I assume with the IRA. Also the Red Army Faction, which IIRC trained outside Germany.
But what external group would fund, supply or host training for NAZI partisans in Germany after WW2? The Soviets were generally willing to sponsor trouble in competitor nations... but i have trouble picturing them supporting Nazis, especially as they were occupying a big chunk of Germany. So probably no external support.
3) unsettled/uncontrolled domestic conditions: post-WW1 violence in Germany; the Baltics after WW2; Palestine; South Vietnam; Africa and other late- or post-colonial regions.
The second time around, the victors actually occupied Germany and administered it comprehensively and effectively. Also, Germany is fairly compact, unlike other examples. The unsettled conditions really didn't last long nor were they ever as great as in post-WW1 Germany.
None of these rule out small-scale terrorism, nor brief abortive resistance attempts. But I think they effectively rule out terrorism/resistance on a significant or enduring scale.
Anybody care to weigh in on the above, or add other factors?