The lighting issue on the wheels almost looks like the normals are backwards. Could you place the skeletal mesh of the car somewhere in the world and try to move some light around and see? I wouldn’t expect this to be a vehicle specific problem as again it looks more like the normals are flipped.
I’ll have to take a closer look at the suspension issue. It definitely looks like a bug. One thing you can do is bring up the debug window with the command showdebug vehicle. In this window you’ll see the suspension forces. If you’re driving on a flat surface the force graph should be flat. I’d be interested to know if there’s a sudden spike here.
, I’d have to see exactly what you mean for the rear wheel drive. However if I understand it correctly it sounds like it may be related to the differential of the wheels. Are you using rear wheel open or rear wheel minimum slip? If you use minimum slip the car’s differential will actually modify the amount the tires rotate. This is used when one tire is on ice, for example. I’m not sure if this is exactly the cause though I’d have to take a closer look.
UPDATE: Sorry I also forgot to mention that if you’re using rear wheel drive it makes sense for the back tires to spin more slowly as they are actually applying torque on the engine, which is still in some gear, while the front wheels are actually free to spin. I believe this is the correct behavior.
Hope that helps, please post more videos it helps.