I've not checked the replay yet, but remember that odd suspension travel and other things like that can also be caused by lag - and I'm fairly certain I forgot to turn my VPN off before the race last night....
Didn't you lower the car height ?
No, but these seem to be running some pretty grippy rubber so my slides load the hell out of the rear
These are the AC version too remember (Mk3's) so have independent rear suspension instead of the carthorse rubbish on the Shelbys, the body model is actually from an old 427 Shelby model back before the Kunos car was released. So the graphical glitch is likely due to those factors.