If you are determined to purchase a trailer, you may as well get one that will do more things then simply carry a canoe or kayak. For that is the only thing the one you show will do. Other then that, it will gather dust and waste space. A light weight folding utility trailer takes up little space, and can haul many more things then just a little boat. Rather handy things actually.

You will also probably damage or even break your boat with a trailer. A trailer gives a much harsher more violent ride then an automobile gives. The shocks of hitting potholes will be transmitted to the boat far more effectively then a car would with it's softer springs and shock absorbers. There is also the vibration that comes with a trailer, and having it steadily in the stream of debris kicked up from your tires that will quickly scratch up and ding the surface of the boat.

If you want light, go light all the way. I have a utility trailer for my motorcycle that weighs in at 40 lbs, including the cargo box. The trailer you show is far heavier then it needs to be for the load. Mine has a GVW of 400 lbs. However, with all the surface area a kayak gives to catch wind there's a darn good chance that you will manage to flip it and drag the boat down the road with the trailer sitting on top of it with a twisted tongue. Or at least pogo sticking it so badly in a wind that other vehicles will be struck by it as they go past. Resulting in your causing an accident, being liable for their damages, as well as smashing up your boat.

Why are you so adament against transporting it on top of the car?