Hot Racing hop-ups
 

It looks like Hot Racing has a bunch of hop-ups for the Micro Rally/SCT. I've only found thetoyz.com stocking them so far. The aluminum spur looks particularly interesting, if paired with an alu pinion. The plastic stock set looks like a weak point, especially if you go brushless + LiPo.

I haven't tried any of these yet so please post if you have had any experience with them.