How can they have never painted a urethane bumper before? they are a body shop right? they have been around right? well aren't most stock bumpers urethane? well if they have ever painted a car or even just replaced a stock bumper from a rear end collision then they have painted a urethane bumper.... if u ask me somthing sounds fishy.... and urethane primer??? I never heard of that... if needed why wouldn't they just trough the flex agent into the primer so that it can flex just like the paint??? Im not sure if thats how it works, but I stand by my point that they have to have painted a urethane bumper before.