A couple of thoughts on cartopping.

I started out with the ubiquetous(sp) blue foam pads, front and rear bumper lines and a loop through the windows. The first time I used them was to take my boat home from Wooden Boat School in Maine. My classmates at the school were skeptical that this setup would work. I stopped to check the straps every hour during the 450 mile trip home. I made a few adjustments to cut down on wind noise and kept my speed in the 55-60 range. The boat would rock a bit from side to side, but I don't think the boat moved a millimeter fore and aft on the trip home. I used this setup for a season. It's perfectly secure, but hard on the car's finish. You can't help but pick up dirt on the foam pads, which abrades the paint on the roof. And it's awkward not being able to open the rear doors on the car until you take the middle strap off.

My next step was to get a pair of el-cheapo crossbars to mount on the roof. I put some circular pipe insulation over them. Because my car is a gutterless design the crossbars were not fastened down as tightly as I would have liked. So I continued to use front and rear bumper straps. I found that I could put my hard-chined CLC boats right on the crossbars, tipping them one way or the other so that one bottom panel would lie flat.

My girlfriend had a pair of Thule saddles on her car. After using them a few times I broke down and spent the $$$ for Thule crossbars and the newer H2GO saddles. There are worth every penny. The saddles are easy to adjust to fit either my VCP Pintail or my CLC boats. When carrying the hard-chined boats I adjust the saddles to make a very flat Vee which conforms very well to the bottom of the boats. The Thule racks are so solid that (and I know I'm going to hear about this) I no longer use bow and stern lines, which prevents abrasion against the bumpers. Unlike my previous setups, my boats don't so much as vibrate at speeds up to 70. The Thule crossbars fit so solidly that I think the roof of the car would have to deform before they would come off.