Now that is a strange error!!
I think the car.wad is missing a texture, hence the wheel rim is white.
I also think that perhaps the co-ordinates of the right rear tire has been shifted to be WAAAAAAAAAAAAAY off the car. I dont believe that the game would run without a missing wheels. Download Team Editor if you dont already have that, and you can modify the position of the wheels. If the centre is 0, then the left wheels are usually -70 and the right are 70. Maybe Team Editor will show a big number for the right rear.
Hope thats a bit of help.