Let me start with, while my wife has a Wave, I have never actually tried to put one on a car-top. I have car-topped similar boats.
Physically, you could put a Wave on a car-top. Assembled, you will need at least 2 people to lift it. Disassembled, you can put it on your car by yourself but those hulls are very awkward. Anouther problem is all that other stuff (mast, sails, rudders, rudder connector, etc). The Wave platform and mast alone is equal to the max safe car-top weight (170 lb) so the rest of that stuff has to go inside. In a small car that will leave you with almost enough room for the driver.
Car-topping a Wave will be like cartopping 1 and 1/2 Lasers. If someone said "I have a pickup truck and I am going to cartop a Wave on bed racks to avoid owning a trailer", I would say "cool". If someone told me they were going to car-top a Wave on a Civic, I would say "lets see if we can find you an old trailer".
In summary, you can do it but it will be a lot of hard work.