Not wanting to spend hundreds of dollars on a cartop carrier, this foam carrier and straps is a great value. I'd recommend this to anyone who wants to paddle, yet has a limited budget.
The carrier works well enough; the boat felt quite secure on a 60-mile highway trip at speeds close to 65 mph. Two minor concerns -- the V-shaped tie system puts a fair amount of strapping in front of the windshield, and the wind effect can be quite noisy even at speeds as low as 30mph. With a 12-foot kayak, there's a lot of extra strapping to be tucked away. But it's hundreds cheaper than a hard track, and can be used on any vehicle.
I was a little nervous at first having used the Thule set up on a friend's car all season but it worked just fine. I added locking caribiners to make myself even less concerned and the kayak stayed up on the roof of my small car on highways and back roads with no problem. I'll be using this set up a lot next summer!
I was initially unsure of using this, but it was recommended to me as an easy, inexpensive way to transport my kayak (I have no roof bars). All the buckles and straps stay where you put them and hold the kayak very securely. Good directions included also.