If it's going to be 4x4 Xterras only the MAKE it 4x4 Xterra's ONLY. Do not allow any Frontiers or Pathfinder or Murano or 2WD Xterra's to register. And if they do make sure they are clear that they will not be able to participate in any off-road or social event.

Heck....Make it by invitation only, since it's so exclusive anyway...