I'm considering adding PVC trailer post guides to my boat trailer. The trailer gets lost behind my truck when retrieving boat. My trailer tubing is 2"x4". Any ideas on how I would attach the guide posts to the trailer frame? I was going to use u-bolts but can't quite figure out how to attach one on the top side of the trailer frame and one on the bottom on each side (yes, I need a drawing, sorry). I could always drill through the trailer frame and attach u-bolts that way OR simply drill through the PVC and the frame and attach with stainless steel bolts. Have any of you attempted this project? What worked for you?