I too miss the race mods and the used cars...Some of the cars in gt2 that you didn't even know you could racemod and when you did it's like "My god that car's insane!" And used cars save the day...There are some real gems floating about in the used lot not to mention some of those rare cars you get in so many cycles of days.
More cars! The new car lot is rather skimpy...Gt2 had an amazing car lot...both new, used, and prize. Also I hate the random car win thing...at least in gt2 it was a surprise! You had to go check your garage after a race...With this it's like, "You've just spent two hours on an endurance race...We know what car you what, we'll float it around in front of you, but we won't give it to you!"
Track Diversity...There have to be more tracks...The monotony in GT3 is almost unbearable...I want a bunch more tracks, varying time of day...to be able to race any track in morning, day, dusk, and night. Also tracks, like city tracks, to have more than one route, a cross city race I think would be fun. HP restrictions need to come into play and more dedicated races...