Well sadly when you damage the car in some way, there are holes in certain parts which cause fluids to leak out. It can be fuel, oil, hydraulics,breaks,cooling, etc... which make it harder to operate the machine. I was thinking of a visual approach to this to show stains on the road or on the car itself in the appropriate areas
That's a cool idea, but we already have coolant leaks. Don't know if you're talking about physical leaks, or mechanical leaks.
I'd like to see this as well. If you wrecked your car, oil + coolant could spill out onto the track. If another vehicle drove through it, it would effect their traction.