I've reworked some of my favorite cars into rail cars with power modules and a hover inside. To compensate for the high cpu cost of the module, I had to make the cars shorter by 2 blocks. I think I kind of like the shorter versions better and they are really fun to drive.
I basically started using rails because after the epic crap box update my smg's seemed broken (I know they just got a fix though) and my plasma seemed weak. I found for me rails were my new weapon of choice.
I started using hovers inside to compensate for the horrible steering my wheels had after the update. This gives cars great turning and lets them climb really well, and I don't need steering thrusters anymore.
Anyway, that's the story of the mini cars!