We offer two different styles of the park brake locks for your VW dune buggy or VW Sandrail. The two styles are the hydraulic park lock and the brake proportioning valve. Hydraulic park locks are designed to be installed in the main brake line that runs to the back of the car. With installing these on your Volkswagen, it will ensure that the car stays in place. These VW dune buggy park locks are simple to install on any VW and are just as easy to use. To activate the park brake locks on your VW dune buggy or VW sandrail, you just push the brake pedal down, push in the button on the VW park lock, then let off of the brake pedal. In doing so, this will cause the rear brakes to lock into place. To release the rear brakes on your sandrail or dune buggy, you just tap the brake pedal and that will cause the park lock to release. The brake proportioning valve can be installed on all dune buggys and sandrails. With this installation, it will allow you to adjust front to rear brake bias with a twist of a knob. The proportioning valve makes it a seamless adjustment on your VW. If you have any questions, please feel free to contact us at 1-800-955-9795 and we will get you taken care of.