Racing Tank. Because racing and tanks totally go together.
About this creation
Well, as I mentioned in my S4AS "White Light" MOC, I recently bought the Lego Racers set, Blue Sprinter. Within 5 minutes of opening the box, my set looked like the cover art. Actually, the wind up motor worked all right, propelling the racer about 5 feet forward at high speed. (For a Lego pull-back)
Within 7 minutes of opening the box, my set looked like the above photo. (My official Lego sets tend to have a very short lifespan) I actually tried the racer again, using just the basic frame. You'd think it would have gone farther faster, but it didn't. Instead, it accelerated really quickly, did a wheelie, hit a 2X4 brick I had in my Lego area, and flipped over, killing the non-existent driver.
Then, I remodeled the car. At first, it was just to see how well the pull-back motor could propel a basic frame using treads. Did it work as well? No. Did it look as sleek? Hell no. Was it funnier? Yes, and so I continued building my mad vision of a racing tank.
Armed with a huge 16-cylinder engine producing infinity minus one horsepower, the racing tank has an amazing top speed of...
damn, only 25 miles per hour.
Huh, maybe a racecar would've worked better. Oh well, back to the garage.