Topeak MTX Rack fixer

I was in love with the Tailfin aeropack, but it's too expensive for me.
The idea was to build something similar but mutch cheaper.
I bought the Super tourist rack from Topeak (30€") and a mounting plate (4€)
The waterproof duffel bag (30L) I already had laying around.
You can also use a Dry Bag (you find lots of them on Amazon)

With the fixer I can now remove my trunk bag easely and fast...

The design makes it possible to build your own trunk bag.

Please, I'm curieus to see your makes or remixes