A coastal road trip requires a specific kind of packing. You need gear for the water, gear for the camp, and a system to keep the wet sand away from your dry clothes.
Board Protection
If your boards are going on the roof, they need protection from the sun and bugs. A padded surfboard bag is mandatory for highway speeds.
Food and Drink
Hard coolers take up too much trunk space. We prefer a backpack cooler. It fits behind the passenger seat and you can easily carry it down steep trails to hidden beaches.
The Wet/Dry System
Always keep two heavy-duty dry bags in the car. One is for clean, dry clothes. The other is a designated "wet bag" where all sandy wetsuits, wet towels, and damp boardshorts go. Never mix the two.