Ok i have searched some forum but I have found only threads about OOS Error which occured due to version incompatibility. Mine is quite different, it happens when You watch replay right after You have saved it and press Shift+R to restart race just before replay ends and after that You get OOS Error and when You hit Shift+R againd strange things tend to happen. You are going to be switched with AI car, Your hands and wheel shakes, sometimes physics is strange (car jumps like bump damping, rebound damping and stiffness was set to maximum), number plates on Your car shows name of AI that used to be in that car, Your car is on grid with number plates You have choosed in options, happens that rear wheel camber in that car is changed (car You suppose to be in) and when You hit that car it changes colour same as car You are actually driving but the car You are in changes to color choosed by You in garage. I know it's quite confused + my English is not perfect so it can make my discription hard to understand so i have recorded a video(its short because i had free fraps only and it is not so good quality as i want it to be (original nice quality weights over 500mb) but i think its enought). Below is the link:
http://www.youtube.com/watch?v=zksizV7LNTs

EDIT: I have notice that not only You old car may have tuned setup (camber) but also some AI drivers have changed setup.
EDIT2: Other AI cars after crash can change colour too, BF1 and LX6 have +camber, FZ5 have much shorter gear ratios, Race Bout have lowered front (not sure)
EDIT3: If You choose only one type of car (All AI and You) other bug occure when You try to restart race: there is no OOS Error but replay is restarted and colour of Your car and numberplates are changed

Thank you - this is fixed in 0.6B5