Vtol Jets and Railgun.

[meeksorad]

Rotating Thrusters. I know you can use hinges but I want a self-contained VTOL thruster. It would be cool. Also, a single shot Railgun that shoots a massive projectile that basically nukes in a small area. Of course, it would be extremely energy heavy and probably not able to get the energy reducing upgrade. (otherwise, you could one-shot win.)

Or maybe make it a tube-like structure that your able to fire TNT from at high speeds like an orbital strike cannon. So either a decently big gun or a massive structure that fires tnt. It would be fun to have.

[Micha]

The new racing update has rotating VTOL Thrusters

[Lurkily]

You can make both of these.  Projectile count, minigun, and accuracy upgrades can make a pretty devastating blaster.  I've personally made magnetically accelerated TNT launchers before; the accuracy was, well, less than I desired, but I put guidance sensors and thrusters on it, which did not help much.