That's pretty impressive that any part of it was able to work at all, honestly... version 1.2 is pretty ancient, lol. The game's code has changed significantly since then. The good news, though, is that I'm almost done with the next release (which is going to be a pretty massive update) and it should make it quite a bit easier to add the hybrid system to other vehicles. The major release after this coming one should make it even easier, but it's going to take even more work. I have a lot of restructuring planned for that one.