I have 100's of feet of used climbing rope and want to make a scramble net for my kids to climb on. What type of knot(s) should be used. How to make each square the same size?

It's for my subaru wagon? I just want to throw the snow tubes up there this winter and strap them to the roof rack. I saw something on the subaru website but I don't wan't to pay dealer prices. I'm just looking for a small net with a few hooks.

purchased a trunk cargo net from dealer.. the upper mounting is ok but to fasten to floor of trunk have to find /dimples / per instruction and drill can't find dimples can i drill anywhere to fasten the net to the floor of the trunk ???