I have this really loud annoying and embarrassing squealing coming from the passenger side of my van. This squealing happens randomly and is usually in the front passenger but occasionally in the rear passenger side. My kids hate this noise they are embarrassed but can't help but just laugh now because there is nothing I can do to stop it. Everytime I have someone look at it, the squealing never happens for them therefore I sound crazy to them. What is this squealing!