Need some help by way of your experience. I have a friend that builds Receiver Hitch Platforms for bikes and trikes. I would like to build a Receiver Hitch platform for my Motor Trike Goldwing (IRS) that will hold a couple of bags or at least a bag and small cooler. I have seen several sizes on the web but not much feedback. I am looking at something about 28" wide and maybe 20-24" deep. If any of you are using a rack/platform, I would really appreciate your comments - concerns - suggestions - and experiences. Solid bottom? Lipped? etc Thanks in advance for the input.