UPDATE: v2 of this was not very reliable.  This one has an integrated spring in the print and seems to be holding up very well so far.If you downloaded v2, please grab this one instead.This is my second such mount. The first was two pieces that had to be glued and relied on a friction fit.This prints as one piece (best to use support, Slic3r's support works most excellently on this part) and also has a bump that engages the retention groove on the taillight.