I agree with Manny; Grid Autosport is a Codemasters Greatest Hits package and very much a 'sorry' to the fanbase. Grid was arcadey fun in it's day and I didn't mind Grid 2 (sold to me on NeoGAF as sublime PGR-like but it isn't) - the physics were a lot more tuned to drifty slides and the cockpit view was stripped for more visual bling.
Grid Autosport is a return to the sim-light releases Codemasters were famous for back in their TOCA days and their F1 releases. The cockpit view isn't as detailed as it should be however the blur effect reminds me a lot of the at speed look of Slightly Mad Studio's NFS: Shift and Unleashed along with Project CARS.
Physics are a mixed bag; muscle cars have the handling of a greased brick on ice, the touring cars feel okay when the AI isn't punting you off and the open wheel cars naturally have the most grip and are akin to the F1 games from CM. Thankfully the drifting is very easy compared to Grid 2 (I found the cars used in races far easier to drift) - I say thankfully as I don't much care for the difting events.
I had a heck of an experience playing DiRT 3 on PC with a Logitech G27 hooked up. Bit daft given the amount of twitch steering you need to do in that game, but builds arm muscles!
The Gran Turismo series works well with the G27 also. Cracking fun.
Assetto Corsa is great on PC with my G25 (and it isn't even finished yet). I also concur with Manny Brown, Gran Turismo is also very good with a wheel. GT6 also fixes alot of the issues that people had with 5. Still looks great on the PS3 too.