I am trying to find some c channel with a lip where I can slot the head of a bolt in at one end and move it along the length. I am trying to mount my roof tent onto my roof rack and my used Howling Moon tent did not come with any on the bottom. Instead it has 8 holes and 4 U bolts which are in the wrong place. I have tried a few metal stockists but they only have c or u channel. I have tried Douglas motors for their tie down channel but that will not work apparently. Worse case scenario I will bolt the tent onto the rack but his means opening it and climbing into it while its on the roof.