Yeah turns out it wasn't the car. I was having BodyShop problems too (Sims showing up red in the bin) and so once I got rid of the car I thought it solved everything. Turns out no I have no idea what to do.
I fixed this issue by putting "optimized rendering" back on for just one run through. It fixed the graphics issues, but made things run super slowly (always did). The next time I ran the game I deselected the optimized rendering and it was back to normal gameplay speed but the graphics glitches remained solved. Good luck!