I wasn't happy with the original original acrylic carriage. It used two widely-spaced screws to mount the hot end and they ended up bending the acrylic. (see: [http://www.thingiverse.com/thing:2172906].) While I was working on a better mounting system I also added a place to mount a part-cooling fan and an adjustable mount for the BL-Touch.
This version uses four m3 screws to mount the hot end--you need two copies of the collar part.
The BL-Touch mount was designed around m2.5 hardware although I ended up using m3. It can be attached a number of different ways depending on the need.
There are two extra screw holes on the front of the carriage. I was thinking of adding either a clip for the cables or a second fan mount. In the next version, I'd also like to integrate a belt tensioner and a cable chain.