I was exploring the latest update and some of it's content. Its so much i hardly ever get around getting to know all cars. I can imagine that finding all the bugs with so much content is quite difficult. These errors are not hardware related, but bugs in the coding. The Caterhams completely quit the program to desktop at Brandshatch (even after Steam verified all content twice). While all other cars runs fine there. When driving behind a F-Vintage car @ Oulton Park (classic) it's right rearwheel is popping visible/invisible at close range. I suspect a LOD value error, as it's just that one wheel that has this behavior. When doing a rolling start at Oulton Park (classic) the whole race restarts it self to the beginning of the rolling start. So you get drive all the way just beyond S/F, than instantly you zip back to were the game started. Like you get stuck in a loop. Pressing esc. gets you back to the menu. Trying again gives the same result. Probably some error in the AI file. I guess these things are easy to fix. If i find more i post them.
Since these seems to be reproduceble bugs, you should post them on the specific bug thread (for better control and it's where the devs go first): Automobilista bug report thread (Please read the opening post)
Not sure we can answer in the bug report thread, but I just tried these scenarios, because I did not recall having these issues before. I still don't. All Caterhams run fine at Brands (GP and Indy) with 15 cars on track. No missing wheels in the Formula Vintage at Oulton Classic. Rolling starts are fine too.