I start my car up today and everything is running fine. I stop to pick-up a friend of mine, turn off my car and leave it for 20 minutes. I get back in my car turn it on and start to leave when it sounds like I'm dragging a bumper under my car or something, by the way my bumper skin fell off yesterday and it dragged under my car for like 30 feet. Now I just have the rebar. I look under my car and see nothing hanging down or dragging. so I start going again and I hear the noise, I let it go and when I get up to 40 mph it goes away... any ideas?