Seems most of the modern cars have these very light duty pack racks. Why not something from old where one could load the tent and a stack of camping gear. Saw an old ford station wagon which had the roof loaded with gear. The Yeti should be a good candidate. These rail systems seems very light duty.

Edited 6 November, 201114 yr by TomAU

Safety I guess, genuine roof rails/bars and boxes are crash tested. Imagine being stuffed in the back and a tent pole coming through the back window from a overloaded roof rack.

I think the limit for the Yeti is 100kg, so it isn't that low!