The Porsche Cup 911 (the slow older fun one) has a major AI issue at Laguna Seca. Going up the hill to the left "kink", the cars get loose and always spin on the first lap. It makes AI racing there very difficult as some of the field bunches and is very slow for a lap or two and the rest of the field checks out.
for porsche 964 ok I've seen. a patch is being tested and should be available on the december release.
I can confirm a bug on Laguna Seca. It's actually more an error with the AI line (Ideal. line). When i tuned the line on, i noticed a very small kink in it, just over the hill after the start finish line, so all the cars come to a complete stop, drive the kink, then continue.
I can confirm it is a Racing Line/Track bug. I tested all lmp, gt, tc, adac, and dtm cars. All AI cars think there is a tiny chicane just over the hill after start , finish line at Laguna Seca.