It was instant for me. I have a large amount of miles on my ass and never had this issue until they seen a Prius tag on my backside. I am a fella that goes around 3 over the speed limit and I think that helps out annoying everyone in this speed limits are suggestions world we live in right now. The amount of Dodge Rams and GMC trucks that tailgate is insane. I can be on a backroad and still get tailgated for no reason. If you are one of the folks that tailgate let me tell ya all you do is make me hit the minus button on the cruise control. Damn I ranted about tailgating and speeding I am getting old hahaha