It's most likely the driving line Polyphony has assigned to the AI. They seem to hit the walls most notably through the Massenet and Casino turns, Nouvelle Chicane, and the Anthony Noghes section (the final turn). They seem to be fine for the most part for the rest of the track.
The Nouvelle Chicane is the worst for the AI driver on the inside as they always hit the inside guardrail heading into the first turn of the chicane, making him back up, and that always causes a problem. I always tell my AI driver to pace down here and follow the leading car through this section (though honestly, I don't think you can actually tell him that), but he doesn't listen.
The same can be said about the Anthony Noghes section. I had a Super GT500 race here once and one of the AI drivers decided to screw up here by hitting the inside wall just after the pit entry, and somehow ended up sideways. This caused a massive jam for the rest of the pack (I was the only one smart enough to just go around). It took them almost a minute to sort themselves out. The AI is too religious when it comes to following the race line that they'll rarely (and I mean rarely) deviate from it, even to avoid an accident. They'll just slam right into you with little to no regard to safety (I know it's just a game, but damn man).
Polyphony needs to adjust the line (the inside line primarily) for these two corners, or open up the Nouvelle Chicane a bit. PD does have many sections closed down tighter than they actually are supposed to be, primarily from the lack of a proper penalty system. The only time I really see an AI driver lose it in the Casino corner is when his car is loose in the rear (i.e. loose suspension settings in the rear).
What are the regulations for the Seasonal Race?
