Hitch receiver mount for aero mod?
 

This weekend I saw one of those cargo support bars that hooks to your hitch receiver and was wondering if such an approach could be used to attach an aerodynamic rear end to a vehicle without modifying it permanently. Since my car's under warranty and I have a hitch that would be highly desirable (not to mention wanting to use my hatch back now and again). The trailer connector lets you hook up remote signal lights easily and a clear section and attention to support placement could allow the rear view to be relatively unobstructed. Have to relocate the license plate and I'd want to check other legal issues with the guy who does my inspections. Ideally, the frame would fold up, but that sounds like version 2 (...or 3). I am reasonably handy with a welder (far from an expert, however). To keep it light I'm thinking tubular frame with heat shrunk membrane over it. Any ideas?

I think it's been done and was successful.

I would probably start with a Hitch Hauler:
https://www.discountramps.com/cargoIm...-carrier-3.jpg

and add something like a rooftop cargo box standing on end:
https://cache.jalopnik.com/assets/res...into_Rr_LH.jpg

If I'm going to have some big ugly thing hanging off the back of my car attracting attention, it can at least carry stuff (and then I won't have to move it to access the hatch; instead I'd just put the stuff in it instead).

Another option to save time on fabrication would be to use a fold-down bicycle carrier. That way, you can just fold the whole assembly down to get access to the hatch.

https://www.hitchsource.com/images/DuraRck_onSUV.JPG

if you wanted to be cheap, you could start with a hitch extender and bolt on components to that. if you knew how to weld and had access to equipment, that may be an option as well.

I don't have a 2" hitch, so starting with a standard device is a non-starter. Good to hear it's been done successfully! I assumed the forces would be more than manageable, but it's good to get some confirmation. I figure if there were some foam on the edges and a clamp you could turn to wedge the tail against the rear of the car it'd help a lot with any tendency to rock back and forth.

I'm not too worried about fabricating the frame since lightweight tubing is pretty cheap. It's more the skin that concerns me.

I have a Lincoln wire feed welder, BTW. Got it last year to make a rip fence for my table saw. The aftermarket ones were so expensive that it wasn't all that much different in price (and I got a welder out of the bargain). I also have a hydraulic pipe bender. Oh, wait, that probably can't do thin wall tubing. Maybe I'll nab a conduit bender.

I guess I'm looking for a compromise between size and efficiency. Want to stop at the diminishing returns point. Need to do some sketches and research.

A bike rack is definitely available in the smaller receiver size. I think there are hitch haulers for that size too. Granted, they'll probably all be more expensive than fabbing your own.

Really? Wow, I just assumed my dinky little 1 3/8" hitch wouldn't support it. Too much time looking at ones made for trucks & SUVs I guess. I'll take a look. Won't hurt. Imagine the design phase of this will take a while, although this is one project I actually want to build (most I post about are hypothetical).

Because I removed my rear seats I can put most stuff in that way.

Looking at my car a bit I wonder if I could make the rear in two pieces. The bottom part would attach to the hitch, and the upper part would replace the hatch. I presume the hatch has some role to play in crash safety, so not a serious option I guess.

I suppose I should realistically start by determining the longest setup I'm willing to drive.

Had a really weird idea. What about an inflatable rear tail? It could even be clear in places still. A compressor could account for small leaks. I can see a couple ways to have it deflate in a controlled manner that would keep it from dragging and shorten the overall length.