I was thinking today, that it would be sweet to see a car racing game come out that combined the best aspects of Grand Turismo (the physics and car upgrades) and the latest Need for Speed (the game mechanics and AI, as well as the nice world), and then expanded the car selection to some ungodly ridiculous level, as well as up the amount of customizing you could do, and add more upgrade capabilities. Make it an MMO, and you'd have an awesome game there.
I'd like to have a racing game where it tracked the milage on the car, and adjusted the trade-in value realistically, taking into consideration the upgrades that you've done, and see multiple years for the different make of cars. (Grand Turismo did this a little bit, but I'd like to see more).
For instance, I'd like to see ALL the variations of the Porches, and ALL the Corvettes, and ALL the Mustangs etc, etc... Rather than just one or two different models of each. Maybe have used car lots in-game, as well as new car dealerships. The cars could be actually traded in-game between players.
So why don't you programmer types get to work on that.
