I've seen kayaks mounted to cars, trucks, vans, PUPs, TT's, RVs, and almost any other kind of vehicles with these racks: SportRack Standard Block Island Foam-Block-Style Kayak Carrier - Roof Mount - 12" Long SportRack Watersport Carriers ABR525
I have three Thule kayak racks on my pick-up, but when I am going fishing by myself, I'll usually just throw one 'yak on top of my Jeep with a set of the foam racks. They work great!
2014 RAM 2500 Laramie 4x4 Quad Cab w/Cummins Turbo Diesel, 2009 Rockwood 2607, and 3 'yaks!
300W of Suntech Solar, a Rogue MPT-3024 Controller, and a Xantrex PW2000 Inverter