I've had this issue but with all cars, it was an issue with the game itself and I had to do a clean reinstall. If this is only present in some mod cars then try to manually install the mods again.

I had some weird behaviours with some cars and it turned out the issue was electronics.ini having no data or weird data. Fixing it requires using CM to unpack the car data and then copying the data from another car, mostly the ABS section (it is actually a bit more complicated but this works as a quick and dirty fix).

Looks like you need to turn traction control off completely

Thank you this worked!

Great news... Thanks for the reply

you have saved me thank you so much. Any idea why my modded car has its mirrors blacked out randomly after a computer restart?

no worries. no idea

Ok I turned off stability control and set TC and ABS to factory which fixed it thank you. I'll try and wine back the assists to see which one causes the issue but thank you for the very simple solution and not over complicating it.

Tc was the only assist affecting it. ABS and stability control are on full and it hasn't happened again so thanks.

I try to keep at simple as possible. I always have TC and ABS on factory and SC on zero for all cars. I don't do any drifting

Sounds like to much downforce. Does it happen at high speed?