I got sick of my roof rack system for a few reasons;
> it was too tall for some car parks,
> I had to always attach a sling to the front of it and secure it to my bumper so I could pull the board out of the bag and leave the bag on the roof
> Even with the sling on the front, I still had to unzip the bag at the side, reach in between the bag and the board and unstick the wax in the area of the rack before I could pull it out from the back.
I had a few Litres of epoxy resin I didn't want, plus a lot of chop strand glass so I laminated up a big flat board about 21 inches wide and a bit over 3 feet long, glued a few strips of carpet tiles onto it and then put it inside the board bag before bolting through the board, through the bag and onto the racks.
Basically, I now have a board bag permanently on the roof and I don't need the multi story racks, unless I go on a trip and I don't need to use the sling.
If I want to keep the board off the car and I don't want to go to the trouble of unbolting the bag, I just take the board out, fold the front and the back of the bag in on itself and tie it down with the tie down straps that are always on the rack.
Only took 3 hours to make and that included 2 hours of laminating. (epoxy is difficult to use with chop strand matting)
Tried it out this arvo and she worked pretty good apart from the fact that the carpet tiles were a poor choice because when the board is wet, it's hard push back into the bag because the wax grabs.
Now that I know it works, I may try something like a really thin exercise mat.