Eureka!
I finally had time to mod my superslick into a carpet crawler. Don't have a digital camera but will tell you exactly what I did.
1)
www.lego.com - order part #10048 small wheels set. These are great. These lego wheels almost press fit onto the car's wheels. You get 8 larger treaded wheels, 8 wide slicks, and 8 narrow treaded tires.
2) Remove both front screws from pcb cover.
3) Using hot knife, cut small sections out of body right behind front wheels to allow for turning w/out binding.
4) Use hot glue or any other medium you can think of to seal holes in body. Dirt in the circuitry is bad!
5) Put small dab of hot glue on center post of car's wheel and press on lego wheel. Repeat until all 4 wheels are attached.
This is as far as I've gotten. It runs great on carpet. The strength of the geared steering allows the front wheels to turn easily. Now I just have to decide whether to make a lift for my 350z body to ride on top, find a truck body at tru, or make a battle bit wedge-style body from some sheet aluminum. Any suggestions?