I know that this has been a hot topic for awhile and many folks have wondered why they haven't been released sooner but new Traxxas CVD options will be available for the slash 4x4 very soon...There was supposed to be a press release this week but I haven't seen it yet. The CVD's are true bolt on upgrades for both slash & pede 4x4s, and 2wd Slash, pede, or rustler (use rears for 2wd)...... The part numbers are: 6851R & 6852R. I think the suggested retail price is $55 a pair.