I know that feeling brow!
I was really hopeful that this MGP15 would be like Ride (another bugged, but better), but unfortunately they didn't!
I've not tested all tracks, but i think that i solve the AI lap times problem for each track... Have a file in DB folder (DB_IDEALTRACKSTIMES.BML) and for Losail, Austin and Assen it works fine... so, based on the MGP statistics files in MGP official site, i've updated all section times for all tracks to the real ones, but i've not tested all tracks yet, so i don't know if is really working... It's working since 1.0 but i don't said because i've not tested, only in this tracks...