I conceived of and constructed this canopy in less than an hour. The design was inspired by conestoga wagons. The canopy consists of two hoops made out of 10-foot-long metal tubing that I duct-taped to the corners of my Xtracycle cargo van extension. I then duct-taped two cross-braces to the hoops and covered the whole thing with Tyvek house wrap.
Thea and I took it for a test drive this afternoon. It was surprisingly successful for a working prototype. The biggest flaw was that the Tyvek was incredibly noisy. We figured we should use nylon fabric such as the fabric a tent fly uses instead. And it would be great if the passenger could zip up the enclosure front and back. Also it would be nice if the hoops spread out more to the front and back like a conestoga wagon, but with some adjustment possible so as not to hit the driver. Would it be possible to make a third hoop that partially covered the driver?
I can imagine finding the time to sew a canopy like this. I would also want to replace the metal hoops with fiberglass tent poles and replace the duct tape with cross-ways clamps.