This could be kind of fun, so you could have regular wheels on 3 corners of the car but a small steelie on one corner to make it look like a spare tire. Another suggestion I have that's related to this is the ability to repair your tire/attach a spare (without resetting the vehicle) if you blow a tire.
So you are saying that all wheels should be individual? Thats a great idea! I cant count how many times thanks to this limitation i have been unable to do something (most of the time in ends on roleplaying or taking pictures for the community screenshots)