I don't care too much for the career mode - it's fine the way it's for me. Likewise with the amount of cars: I'm happy with more than... well.. more than a lot.
But some things are so important and still have been left out:
- Fast-forward, rewind on replays: c'mon, why in havens that's not there!
- Export replays to videos: not a big requirement but it would be great (doing something similar as we already do with photos).
- Have numbers or names on the map when racing online: the red vs. blue approach kind of does not work for real racing simulations.
- Give split times not only between you and the leading driver but between you and the drivers around you (at least the one immediately ahead and the one immediately behind).
- Provide some decent statistics at the end of the race: sector-by-sector times for all laps and this divided and compared between racers. Fastest lap, best personal and on the race, best sector, etc. So many important numbers not even easily visible anywhere.
- Make the multiplayer system work well - the amount of bugs of the multiplayer is just abysmal. Wrong grids, invisible cars, inexplicable damages. Racing online with GT is a pain sometimes.