Looks great to me, thanks
Wheels are perfect now.
Colors can be whatever you want if you have other idea in mind, the only requirement for the texture is it should look old and dusty.
No need lighting colors I guess, lighting will be given by the engine in several ways.
Regarding shadows, well, probably some sort of basic shadowing should be required because the engine is able to calculate lightmaps for static props, but it doesn't make a good job sometimes. I could tell you that with more exactitude if you send me a version of the model with the UV map and basic diffuse map. If shadows are calculated accurately and with no errors there shouldn't be needed pre-baked shadowing.
The end of next weekend should be enough. If you need more time than that wouldn't be a problem if you do what I suggested about sending the model and basic texture. Once it's include in the map then there's some more time to work in the texture.