Guys, chuck all your roofracks in the bin! I've been using
these for ages. Works on any car, costs way less than a proper rack. I've mostly been using for surfboards but it will take a ladder or fishing gear... not good for long journeys or for transporting stuff at 80mph on the motorway but portability is brilliant and they are much cheaper than the 'proper' alternative, and usefully have the tie down straps built in. You can apply a lot of pressure to hold your load on, and easily see how secure everything is from inside the car. No damage to the roof on any car I've used them on, but obviously you need to keep everything clean and not carry a stupidly heavy load on your roof. When you get to where you're going, just deflate and stash in the car.. they won't get nicked. To inflate you just blow into them which takes a couple of minutes, no fancy pumps needed.
There are probably cheaper Chinese imitations but I would recommend getting the Moontubes, the quality is worth paying for. They have a lifetime guarantee and mine are wearing just fine. Usually once people see them in action then they want them. If you are using an inflatable board/boat on holiday and driving to your destination then you can get there, inflate everything and then just throw it on the roof when you need to. Saves you having to mess around pumping things up and then you just deflate everything including the roof rack before you go home. SImple!