I have an 06 grand cherokee laredo, and I'm hearing a rattling noise. It kicks up, and is loudest, when I first start it. I can hear it while driving, and while idling. It seems to go faster when I accelerate. It also seems to be coming from the front somewhere. It sounds like something may be loose, but it's nothing that I can see just by looking. I don't want to have to take it in and spend hundreds if it's something simple. Any ideas of what this could be?