Most everyone by now has made the modification to Sideswipe wherin you swap out the front end (windows as chest) for the back end (trunk as chest) via the small cut notch. I wish to highlight a further modification I made for mine: an upgraded launcher!
Let's face it, Sideswipe isn't Sideswipe without a proper launcher. Since his Alternators form is an 'upgrade' from G1, his weapons should advance as well. His gun is bigger (no wimpy engine block here) and he can now fire 4 missles instead of one.
You'll note that on the original Sideswipe, the white bits on the robot's body matched the white of the gun and missles. On the Alt, the body bits are grey...so, the gun and missles should be grey as well. :-)
I painted the launcher black (since his original launcher was black) and put chrome bolt highlights on the front of the tube (to hint toward the chrome ring on the front of the G1 launcher). The red firing wheel on the back harkens back to the red firing pin on the top of the G1.
Note also that he can use this launcher in both modes!! I drilled a tiny hole into his body both on the shoulder, and on the vehicle mode. In addition, I drilled a hole large enough to allow the gun to attach to the launcher, so that he can use both in vehicle mode if he so chooses.
I'm quite happy with the way this turned out. Below are pics of the prototype sessions (parts pics before paint and prep), including a design that I'll eventually incorporate into an Alt Tracks when I get to it. :-) Parts to make this include a Duel Masters figure (gatling dragon, or somesuch, currently on clearance for a buck at Walmart), while the pinset and gun from a knockoff Optimal Optimus (Big Lots). Any standard pin will do. Get your dremmel, two drillbits, and you're on your way!