I have Green Honda CR-V and along with my dive flag (on the rear glass) and an OMS decal (love their logo!), I also have a little cute green decal that says Compressed air. I thought that was cool, but guess what... On a recent trip over the Battery Tunnel (I live in Brooklyn, NY), the cop stopped me and asked me to open up the cargo area where they saw my tanks... "What are these?" the cop asked... "Oh, these are just scuba tanks, Sir" ... "Hmmm. Ok, these have pure oxygen, right?" "nooo, this is just air, pure breathing air!" "well, I still can't let you in, you have aplaqued car, and we dont allow any plaqued cars in to the tunnel since you have tanks with compressed gas in it." so, he turned me around. Lucky the traffic was light and I had no problem getting on to the Brooklyn Bridge instead in mean time cursing myself out for forgetting to cover my tanks as I usually do. On the second thought... the new electro/hybrid cars that have tanks at 5000psi with compressed liquid hydrogen have no problem going in tot he tunnel. go figure!