There should be an option for: All of them. :X
However, I'll pick the four that the ideas of I'm the most fond of, and explain why (though my interpretation of them may be wrong).
1 -- Pulse Rush, because it sounds like it's something between a Barge (from Blur) and the close-range shockwave weapon from Stage II and the car could do with at least one 'personal space' attack to deter any wannabe rammers
2 -- Orbital Strike. It depends if this attacks directly in front of the car or attacks first place though? You'd have to explain, but it sounds like a strategic/skill variant of a leader missile that's dodgable but at the least going to slow down whoever's ahead of you. Sounds like Shocks from Blur too, I love dodging those.
3 - Spiral Rockets. If they're anything remotely like a driller missile, yes plz. We need at least one anti-leader missile weapon
4 - Plasma Cannon. Because I imagine this thing not really throwing a car in the air, more just flipping it over into a tumble. That sort of crap is fun as hell to see.
What I've noticed though is that 3 and 4 could technically do the same thing, so they may be interchangeable (a medium-velocity, straight-firing weapon that tears through everything?) Which is why I thought about giving them different properties but like I said it's just my interpretation of them, thinking about whether one weapon would have the same uses/utilities as another, seeing whether they may be worth using or not.
And as you can tell I took some inspiration from Blur. Brilliant little game. Terribly underappreciated, just like Rollcage/Stage II were. I like all the other weapons too and I can see them being utilised, but the poll says to pick 4 so I did.