Thanks for the pics Joe - that's pretty much what I was looking for. And - semantics aside... yes - this was meant for an "abbreviated subframe" application.
I love all the documentation of your project on your site, by the way!

Let's define our terms:

Beam axle generally refers to a solid/non-independent rear suspension. The word "axle" implies the driveline.

Rear beam subframe refers to an abbreviated or cut-down substitute for the original square box rear subframe. This design can be used when the rear donuts or hydrolastic system is replaced with coilovers.

The former is pretty rare. The latter is readily available in different designs and materials from several vendors. Assuming you are asking about a rear beam subframe, I don't believe the MiniMania part you listed will work. It is designed like most on the market to mount to the very rear section of the standard rear subframe. The rear beam subframe eliminates that entire back section, so you will need to come up with something different. In my case, I went with KAD's solution, but I'm sure there are others out there. I have some photos and info on my site here that may help:

//joe250.com/cars/mini/rebuild/step58/step58.html

Just wondering if any of the board members here use a separate adjustable rear sway bar on a beam axle suspension? I have what looks to be a beam axle assembly on my car that uses the stock rear trailing arms - but does not include the integral rear sway bar as some kits do.

Anyone use this bar with a beam axle with success?

Minimania adjustable rear sway bar

I'd like to be able to dial in a little more oversteer for autocross. Thanks in advance for any help!