yes, i have a minivan and its a pain to put them up high. I bought the cross bars from ebay it came out to like 80 dollars it was a good deal and just use the ones made for the car.
The easiest and most expensive method is the Hullavator made from thule, once you have the factory racks installed.
Another option is to use the wheeleez and tie it the cross bars to push the kayak up
like this:
http://www.youtube.com/watch?v=IC36CZHfMwo
or just open the side door find the sweet middle spot on your kayak and put one end on the roof and as your pushing the kayak on the roof put one step on the inside of the car where you opened the door to finish putting it up.
If you have only one kayak get the round/oval foam pads that wrap around your cross bars and put your kayak face down.