Im not sure this has been talked about before, if so I apologize to the OP.
We have this wonderful shade we attach to the roof bars on our ute, stop for a cuppa, roll out the small awning and presto a cool place to sit and enjoy the bush.
We spend a fair bit of the time in a static camp, thus this unit can fall into disuse.
I decided to place a bracket on the side of the van, drill a hole in the caravan awning upright and attach the car awning to it. Yes it is at an angle but check the photos, its a great idea in summer and extends our caravan awning by a meter or two. We got the end piece as well.