Garmin Varia RCT 715 Mount for Tailfin Carbon Rack

Update Note:  

V8 .3mf file is revised based on a chunk of model I got from Tailfin.  The new design matches the compound contours of the rack arch beautifully, but I didn't include the .F3D file of that version since I don't own the Tailfin model.  V7 is my own design entirely, licensed as shown.  V8 (the blue one)is a great fit, with better isolation of the bolts from the carbon finish.  I'd use it unless you want to roll your own modifications.
 

R2:  I beefed up the webs for the bolts that secure the Varia mount to the bracket.  My printed bracket broke (bolts pulled through the web) when my bike tipped over.  Should be sturdier now.

Installation:

You'll need to disassemble the stock seatpost mount for the Varia, and use (2) M3x10mm bolts to affix the Varia QD assembly to this bracket.  The stock bolts will probably work, but I'm allergic to bolts with Imperial allen heads so I replaced them.

Uses either (2) M3x14mm bolts with hex nuts, or a small zip tie to attach the bracket to the rack.  I haven't incorporated a retaining strap, but I probably should.

it’s a pretty tight fit.  I put some 3M paint protective film on the arch to protect the carbon finish.