I have been tinkering with the great "instant on/off" PVC loader design you may have seen on youtube. It uses industrial suction cups to mount a PVC cradles to the bonnet and windshields, exactly when and where you need it.
[youtube]http://www.youtube.com/watch?v=LBcPgDx5kJY[/youtube]
They needed to be stretched and reinforced to accommodate the AI hulls shape and weight. I also added large padded rollers to make the job of raising and lowering the 16ft hull a piece of cake. The job can now be done one-handed or by someone who is not a weightlifter.
You just need a 4 HEAD SUCTION CUP from Northern Tool + Equipment, some 1" and 1.25" Sched 40 PVC and the proper plastic glues. Use blue pvc primer and grey PVC glue or a multipurpose cement. You are bonding PCV to the ABS grip. I added a dowel and stainless wood screws to add stability.
http://www.northerntool.com/shop/tools/product_42404_42404?cm_ven=Aggregates&cm_cat=Pricegrabber2&cm_pla=Category&cm_ite=160876Pad the rollers with pipe insulation, tennis balls or pool noodles and "Bob's your uncle".
The improved AI loaders are are compact, light, inexpensive and attach securely in seconds, as you can see.
The 1.25" pipe rollers slip over the 1" PVC frame and allow the boat to glide up and down the cradles. These sleeves are approx. 5" on the bottom and 7" on the side arms.
Makes a huge difference. I used to struggle with a handmade side loader bar. It worked, but required too much time to set up and was less stable.
This design should work great for SUV's and other vehicles with high roofs and steep rear glass windows.
My racks and loaders are all removable without a trace, so except for the smell of wet leather seats, you would never know the car has been to the beach.