Yes, I would say that you can use your APM 2.0 with your nitro car. However, you might want to be aware of the following:
The ignitions on nitro engines make a lot of RF noise that can play havoc with the APM so it should be well shielded.
Also, most electric and, I assume nitro engines, require neutral to be at 1.5ms with full throttle at ~2.0ms and full brake at ~1.0ms. Airplane throttles go from ~1.0 to ~2.0ms so you will have to resolve this inconsistency.
Just a thought.