I have a 2013 335i convertible (aka E93). While I did manage to install the assembly, I did get frustrated at times.
1. Not that it's SH's fault, but taking the facia (which I presume is a fancy word for bumper) off on this thing is not a trivial task. The provided instructions ask to push the clips in that hold the facia, but that is not exactly how the facia is attached. They are not exactly clips, but more of hooks, and big ones. Long story short, I effectively ended up breaking every single hook on the bumper by the time I was able to take the bumper off.
2. I have a 335i, which is a dual exhaust version. The instructions only mention it in passing by saying something along the lines of "attach to dual exhaust assembly". There are exactly zero instructions on how to disassemble the dual exhaust stock assembly so it can be attached to the hitch assembly. That was not trivial and I had to enlist the help of a friend to pull off the rubber O rings that serve as the exhaust suspension from the original assembly. Couldn't do it by myself.
3. The specs on SH assembly state that no cutting of the facia is going to be necessary. This is misleading. When I reinstalled the facia, it completely covered the hole into which the hitch attachment gets inserted. I had to cut out a sizable chunk from the bottom off the facia to expose the attachment mechanism.
4. The two extensions on the assembly that the facia is supposed to attach to are actually not aligned correctly. I had to spend some time bending them to get them aligned with the facia. Otherwise, the facia was being pulled into and under the car.
5. There is a stock plastic mount that holds the facia in the center. I had to remove that as well in order for the assembly to fit. There was no mention of it in the instructions.
6. And the most important issue of all that is not made obvious when you make the purchase: the SH assembly replaces impact guard assembly! This is to say that I am now wondering two things. a) If someone rear ends me, will this damage the actual body (along with the SH assembly) and b) if the car is even street legal at this point in the US without the impact guard.