I was pretty upset with my sc18 when I forst got it as the motor got very hot with little driving and the suspension travel hardly let it drive on anything but my garage floor, I set out to fix both of those issues.
Stock electronics

Got this in the mail from hobbypartz

By
jkvandal at 2011-01-30
Motor comparison...much smaller can but oh so much more power

Looks nice now
So I have the power now I have to get some better suspension travel
Stock suspension travel sucks:

Ordered some RC18T shocks that are much longer

And much better travel now
Next upgrade looks to be some of the RC18T tires, which might require some trimming of the body but I think it will work much better over rough terrain that way. I'll have to give it a solid run with these new shocks first though, maybe I will be very happy.