Here's mine:
It's a classic accessory from the 1960s, the Beetle Bike Bearer. I don't have a picture of it empty
But it is a simple curved tube with straight legs and two two arms to 'bear' the bike.
Originally, it attached with C-clamps on the bumper brackets and a strap to the air intake vents, which was wobbly. The rack is unmodified, but I made 6" tall tube brackets that the rack slips into. The depth of the tubes makes it somewhat rigid.
It's an easy lift for the bike, it's [somewhat] out of the airstream, and is as easily removed as the bike. Here's another angle so you can see the brackets:
