We use a sealed Rivet Nut solution to securely attach the racks to your vehicle. This allows for the mounting hardware to be completely hidden, and the rack to sit as low as possible on your roof. This hardware is actually the same hardware that General Motors (GM) uses to attach factory equipment to their vehicles. While this does require small holes to be drilled, the holes are sealed once the Rivet Nut is installed in place. You'll need a M6 die for your Rivet Nut tool.