Lots of the parts are still available,
http://www2.towerhobbies.com/ are your best source as they actually have the parts in stock. Driveshafts are no longer available, but the MIP upgrades are still available from Tower.
One part that has been difficult to get hold of for some time are the rear arm mounts, but you can get alloy alternatives
http://www.hobbyetc.com/cgi-bin/cata...id=143&man=all