For one. We need pit lights, i get blindsided by noobs flying outta the pits, it really sucks.
Secondly, we need to implement to DQ people by crossing that yellow line after pit exit. Its there for a reason. In F1, you're DQ'ed or fined or whatever for crossing it entering/exiting the pits.
Third, as a partial drifter, I'll be noobish and suggest a mountain, so we keep drifters off of race servers goin YOU ALL ARENT DRIFTING I THINK YOU SUCK and whatnot.
Thats it, I would love the first 2, but could live without the last one. Thx in advance!

Pit lights would be good - especially with the stupidly fast new toy the devs gave us

Pit-line infringements would also be good, and (to me) don't sound too hard to implement. FYI in F1 (and other racing series), crossing the pit-line usually incurs a drive-through penalty.

Mountain tracks/touge courses (and hillclimbs) have been suggested once or twice before and they don't seem very likely. It's good that you're prepared to live without them