Sure, these games always give you awesome weapons to destroy others, but what about the guy without weapons? the one being attacked? I saw that there was a rear shield, but what about some actual maneuvers? In Sonic the Hedgehog: Unleashed, there was a mechanic for dodging obstacles without actually turning, which was to hit the shoulder buttons to strafe rapidly left or right.
If a missile is coming at you, it would be really cool to be able to dodge it with good timing. Combine that with an intense track and multiple opponents, and there is more opportunity for skill, even when you seem to be at a disadvantage.
To that end, another cool idea would be a down-thrust booster, making your vehicle jump straight upward and perhaps avoid enemy fire or obstacles that could otherwise be shot.
Even a mechanic to, perhaps, ROLL to the left or right, working similar to a "barrel roll" in Star Fox. The idea is, instead of just Mario Kart with SuperRebound RC cars, it could really emphasize skill over simply having the best weapon or defensive armament.
It would be neat if, provided any of these ideas are implemented, they are given their own bar that slowly recharges (or even quickly recharges, over the course of, say, ten seconds.)
Base strategies that can be combined with pick-ups could make for some interesting matches, especially if you could, say, choose which base defensive abilities (becoming "phantom" for one second, strafing left or right, boosting straight upward) you wanted at the beginning by choosing parts.
Anyway, that's just one idea I had to try to make it really something-- different.