Hmmm... we have some doubters... in all honesty though... what don't you like about them other then they aren't iconic or are in Firebugs (never played it). I think that a game as insane as this should have some diversity in the vehicles that are available... be it 2, 3, 4, 5, 6, or more (no idea how more... that would be pretty weird looking... 7 wheeler anyone?)
I mean in this combat racing scenario that the game is based in, people's lives are on the line (right? I mean... when these things blow up people die don't they? Am I wrong about this?) So everyone, including the vehicle designers, would be looking for every slight edge they could get. There also doesn't seem to be any rules for vehicle construction either (that I have heard of) so if they thought more or less wheels would give them the advantage, you can bet they would have done it even if in everyone else's eyes the idea is just daft.
Look at the first driverless vehicle race... when people were building vehicles to drive across the desert to win some X prize money (or something like that... I think the prize was like... 10 mil or something) most people went with trucks, Humvee's, SUV's... or something of similar caliber... but one team built their self driving vehicle... on a dirtbike. Most teams couldn't get their vehicles to drive 1000 ft without crashing and these guys hat to try to figure out how to keep theirs from falling over as well. I think the team's name was ghost rider (unironically)
Another story along those lines... I used to be a Boy Scout when I was younger... and I loved making pinewood derby cars each year... I never won, but that's besides the point... I loved building them. Well, one year I saw someone make a very strange car, a design that I had never seen before. They had cut their block of wood down to almost nothing and then spaced the wheels extremely unevenly. They put the two drivers side wheels right next to each other in the middle of the block... barely a millimeter space between them, and then spaced the passenger side wheels as far apart as possible. This was an extremely odd setup but it was just a pinewood derby, so... I didn't think anything of it. Hilariously, it was too light to pass inspection, so the weird solution that the dad came up with was to zip tie a hotdog to the top of the car... perfect weight (I literally can't make this up). That stupid hot dog car won every single race... every one... Why? Apparently the wheel spacing was so drastic that the way the car was sitting it was only riding on 3 wheels at any given time... sometimes balanced on just 2 during transitions. This meant that it had far less rolling resistance than every other car there and gave that dumb hotdog a crazy advantage... I will never forget that.
If it can be done... trust me... it will be done.