Disclaimer: I was not paid for this review, but I was asked by Bimmertech to submit one if I wanted.
About a year and a half ago, I went by a local installer to get a backup camera and front/rear sensors on my 2010 328i. I was given a fair quote and went ahead. I should have known the quote was too fair. The camera itself was passable: the resolution wasn't that great, but it worked. They only installed 2 sensors in the front, saying the other 2 couldn't fit. The sensors themselves were terrible and rarely worked, making noise constantly when put in reverse even when nothing was behind me.
I went to BimmerTech's website and purchased their rear-view camera, specifically the MMI one with dynamic parking lines:
http://www.bimmer-tech.net/bmw-rear-view-cameras/
I also got a rear PDC which enables obstacle detection on the rear view camera, and a front camera (which is possible with the MMI kit and why I got that over an OEM integration one).
The parts arrived securely and were in great condition. I have very limited experience in DIY, luckily BimmerTech has a list of certified installers, and one was in my area. Unlike the installers who were responsible for the low quality parts and install, the BimmerTech certified installers (Unexpected Creations in Edison NJ) were professional, efficient and got the job done perfectly.
The quality of the MMI rear view camera is immensely better than my old one. It fits the iDrive screen and it is great during the day and night. The dynamic parking lines have been helpful as a new driver in helping me perfect my reversing skills by seeing my trajectory.
The PDC is OEM and lives up to the quality expected. The obstacle detection feature is interesting, and the sensors do not seem to go off on false positives.
The front camera is useful for parking and can be used both at day and at night. I think i like it better than front sensors as I can actually see what's in front.
Overall, BimmerTech was great to me, and it was a relief after my past experience with the local installer. From my initial research, they answered questions I had within hours and gave me resources to back up their information. The products themselves are high quality, and I highly recommend them for retrofits. They turned a person skeptical about retrofits after a bad experience into someone who trusts them once more.