How Do I Carry A Board?
First, if you are going to surf seriously and regularly, and you do not own a pickup truck or a long van, a roof rack is essential, and I am talking about not a soft rack but a hard rack. A soft rack is a good temporary solution, but like your wet suit, this is the area you really should not skimp on. People who thought you would be saving some money by getting a soft rack usually end up spending 50% more money by ending up buying a hard rack after a few trips. So don't skimp here, just get the hard rack. You can find them online these days that exactly fits your car. At this time of writing, this set up would cost you about $250 - $300. Better than paying $80 for the soft rack then end up getting the $250 hard rack, since you'd be ahead at least $30 ahead if you skip the soft rack ritual so many people get trapped into.
Also buy good tie-downs. If the tie downs make noise just twist the line a few times before securing the boards. I usually try to jerk the board a bit to make sure that the board is secured tight enough.
When you become a better surfer you can fit your 7'6 or shorter board inside your car (I am talking about Toyota Matrix or VW Golf size cars) if you are traveling alone. But even then you'd want to surf a long board when the condition is small, and if you want car pool with your friends, a rack if a must. As a surfer you will end up needing a solid rack.