I took a different approach by making an internal system using Yakima deadheads. These were bolted to a board which was restrained using straps attached to the interior d-rings. There was plenty of room to hold luggage, front wheels, pump etc. This of course only works if there are no more than two people in the truck which was our case. I believe MB made an interior rack mount available for the earlier MYs but it seemed overly complicated.