I have a 2006 Nissan Sentra. It has about 49,000 miles on it. About 2 years ago I took it into the dealer because I heard strange sounds when backing up to the left side. They seemed to fix the problem. Just recently I began hearing a rattling noise from what sounds like the passenger side of the car. It makes a noise from 0-50 mph. I don't hear the noise as much when going over about 50 mph. The noise stops when I apply the brakes. Does anyone know what this is and how much it might cost to fix? I need to get the oil changed but I will be going out of town for a week ( it won't be driven) and I was going to wait until next week to get it looked at.