Originally Posted by ErOR
Looks like people don't really know what racing sims are, anyway the best you could get to a great racing sim (granted you use a steering wheel) are Live for Speed, Richard Burns Rally<Amazing!, GTR series. Of all those I play LFS the most since there are tweak programs available and you can change whatever you want with the car, plus the physics are pretty darn good.
NFS, Dirt are kiddie games. Luckily here we can return games if we don't like them. I gave Shift 2 a good go but I just couldn't stand it. Little things like once I put into gear and release the clutch you'd expect the gear to engage right? Not in Shift 2, apparently there's a delay between the clutch pedal and hydraulic pump. Don't ask me what world they live in. lol
Not to sound like a dick or anything, but it looks like all you did was read the thread title, and the others' responses. While the title says Sim, if you read the OP's first post, he describes what he's looking for, and in this case that IS Shift 2.
No it's not a sim, but no real sim on the market has everything the OP is looking for. From what I've researched on the games you list, each one is quite niche market-y. He wants lots of "mainstream"-ish cars, tons of upgrading and tuning, lots of real-world tracks, etc etc. While the games you've listed are indeed excellent games, none of them would fill all of the OP's needs, especially when he's looking for something that's Gran Turismo-esque