I've seen them assemble that canopy... Really wouldn't call it "retractible" thought -- assembly took at least 30 minutes -- and all the parts were not stored in the Roadster...
Basically, they removed the passenger seat and welded in some steel plates to support the post. The metal post goes in, and then the solar panels are mounted on the post and all plugged in together.
Neat idea, but the concept is really more of a back-yard solar array that could be on a solar-tracking mount. Put a table underneath it in the shade!