We stayed in a hostel in Margaret River, but it might be possible to camp at the car park (might not leave your tent up during the day). You would need to take water and as it’s not a camp site a fuel stove only. The car park is well off the main drag and farm land on one side. We had a hire car so the road is quite good all the way in. By the way Willyabrup is the only place where I have seen a Gov agency (CALM) take a levy from commercial groups so that they can install and test anchors at the top the cliff for commercial purposes only, these anchors are tested every year and tagged once tested.