I finally got around to ordering keys for my roof rack, sometime this week I should finally gain access to the channels on the top of the crossbars. What I need to figure out now is what to use for bolts. Once I get the end caps off I'm sure I can find something that fits, but I don't know if there is a best size/type or special order bolt or what. If it helps, the main need is for a kayak racks, but I may use it for other things as well.