The sticker stays with the vehicle when you sell it, the plates don't. Of course the new owner could just get the green plates as well if we had that option. I'm not entirely convinced of the merits of allowing single occupant electric cars access to the HOV lanes as a primary purpose of these lanes is to reduce congestion (in addition to the pollution reduction benefits). Having said that, I did put the sticker on my car. (Far left side of bumper - first time I've ever put a bumper sticker on a car I've owned).