I think it depends on what the start circuit is. If you have an addon track thats capable of running 30 cars at the start of the ch'ship, then you can select 30 opponents. You need to be careful though as some circuits have a limited amount of space in terms of garages for cars. Too many cars for garages and you'll run into problems.
You lucky b#¤%tard. Never heard of a minidump.. It means your GTR has never crashed then?
Minidump: When your GTR crashes it creates a file called minidump and it says that in the error message when your kicked back to windows.. In the file are information about the state that the GTR was on when the error occurred, i guess. Don't know the actual information what's in there, tried to look at it with different viewers,dec/hex but i guess you need a special software or such to decrypt it.
Haha no it has not crashed on me yet. But then again I've only had it for a bit less than a week. I've only installed the PTSims GT cars mod and I have a decent collection of addon tracks from here and no grip. I think if you stuff your install with too many mods and add ons the stability becomes worse.