Atomic, Hot Racing and perhaps others are now offering threaded wheel shafts. So you can use a locknut instead of e-clips.
The shop on this site sells them as well (
http://shop.tinyrc.com/home.php?cat=350) and they use 2mm nuts, the same nuts used in XMods and Mini-Z, so it's convenient and a heckova lot easier to deal with vs. the e-clips.