yeah....a lot of guys have made them on here out of PVC and believe it or not a ladder stabilizer. I had the same problem with my Ram. I couldn't see my trailer when backing down the ramp so I made a set of guides for $30 to put on my trailer. You can click on the link in my signature to see pictures of it in my build its toward the bottom. Hope it helps.
An aluminum ladder stabilizer cut in half, U-bolts, PVC pipe. If your going that route, you may want to mount your lights there also. See pics below.
The first 3 are pics of the ladder ext. and some examples of mounting on other boats that were on this forum.
The rest of the pics are of my boats side mounted guide rails, and extended lights.