I'm on my way to get the F40 now to be able to complete my last race in S-series. The Tuned Elise 190 (not the 111) seems to be the best car for all S-races its eligible for. Very fun to drive also.
I was just about to ask you, as I'm having quite a lot of difficulties completing the PP700 races at Fujii Speedring and Suzuka. Have been getting good results with the tuned Elise 111R so far, but just can't get it right on those tracks. Thinking more power would help, I tuned the Nissan GT-R, but fair far worse with that one. Did you use the tuned Elise 190 for those races?
As for AI:
I agree to an extend that the AI is quite basic, but not necessarily scripted, as I've noticed the same scenario happen ahead in the grid multiple times, but only if you repeat the race without quitting. If you completly restart the race from the Home screen, you will have slight variations in the cars within the grid, making for a different race.
I think the AI is good enough. They don't overtake perfect, but good enough. Faster cars will eventually end up ahead of slower ones etc.
One thing I find very annoying though and has made completing the S event rather difficult is the AI. The only way to overtake the AI in the PP700 challenges are by undercutting them in the corners - if you don't get it completly right though, the AI usually crashes into you from behind and *YOU* get the penalty for collision. Or they push you off the track in the corner because your brakes are better - you lose control and then get a penalty for shortcutting (which is ironic since at that point I'm regaining control having just lost 4 positions and a lot of speed AND have to wait 5 seconds...).
Same in online mode:
I've been pushed off the track numerous times while being up in 1st place in my last lap and am the one that spins out of control and gets punished for leaving the track (short-cutting). IMO - the penalty system would work better if the car that is behind that gets penalised if it collides with a car. Especially because it's so easy to push someone of the track and in most cases ruin it for him. Doesn't take more than a gentle push in the right corner...