Hey Guys, I hear this noise from the rear cabin and it sounds like a high speed drill running for about a second at the most. Has anyone got a suggestion as to what it might be? I only hear it on occasion, maybe once every 25km and it seems to be random but I also think it happens after going over a bump. I've got to get the van serviced soon but I want to now what this is and should I be worried about it. Thanks in advance, Conor