My truck is a Travel Bug (Fezz's BIG BLUE BUG). It's a 2004 Ford Ranger... It may not go IN the caches, but it does get logged in and out of each one I go to.
At a picnic recently, we discovered a 213 lb Mile Marker that is a Travel Bug. It is a granite pillar used to, well... mark miles (as the name would suggest).
-Fezz