Strange... I haven't seen that problem before. By suggestion, I have lowered the chassis for all the cars in the hdc file. Maybe there's a small elevation change at the track there (ony physical, not visible) and it causes a collision with the collision model?
i tried Curitiba which has a flat pit straight and it still does it. it is strange as it was fine when i first added the season mod, as i did a full 8 race championship in the mk1 Mondeo, now all the Mondeos cant get out on track.