I have an idea about the handling: it could be floaty at slow speeds and more precise as the speed increases. The ships are very fast so I think the difference would become noticeable. Also the speed loss during collisions with walls should be increased to give the player a reason to slow down. I hope the tracks are suitable for this.
I don't know what I'm saying, I haven't actually played Fusion.

The ships are unbalanced so to avoid seeing Piranha everywhere you could either nerf some ships and buff others or use a performance restriction like in Gran Turismo. Each
car has a number which represents its performance, it can't race in an event if it exceeds the limit.

Add me to the people with ideas but not programming skils.