Full disclosure: I am pretty anal when it comes to the quality and consistency of these types of retrofits on my cars. Most people probably won't be bothered by some of the stuff listed below, but it's stuff I would have wanted to know before buying this unit (and for the most part haven't seen on other's reviews).
This review is for the BimmerTech CarPlay/MMI Prime retrofit on my 2011 BMW X5 (CIC, TCU, MULF, no combox, 360 camera) running MMI software version 3.1.1.4. I am testing using a couple iPhone 11 Pros running iOS 15.1. Note that I am using wireless CarPlay for this review. I imagine many of my gripes would be rectified by using the wired CarPlay, but I don't want to have to plug in my phone every time I drive.
The Good:- The hardware build quality is outstanding. Connectors seem to be of OEM quality. Cables have plenty of length and are nicely wrapped in felt tape. The unit itself is solid with a nice metal enclosure.
- Once paired and connected, wireless CarPlay is pretty reliable.
- Putting the car into reverse does switch from the MMI interface to the (original, not retrofitted) backup camera.
- Installation was fairly straightforward. The included instructions were vague and incomplete, but I found the videos online very helpful.
The Not-So-Good:- Initial CarPlay pairing is flakey. About half the time when I try to pair a new phone, the phone will connect to bluetooth but never prompt for CarPlay. When this happens, I have to delete the phone from MMI, delete the pairing on the phone, and start over.
- There is a bit of a lag for the system responding to the idrive controller. When you turn the wheel, it takes a moment before the interface responds. It is probably only half a second or so, but it just feels far less responsive than the idrive menu.
- When starting up the car in the morning, there is a strangely variable delay before connecting to CarPlay. Sometimes it connects right away, sometimes I am several minutes into my drive before it connects. Also, while it is in this state, the MMI unit is extremely slow to respond. The aforementioned delay between using the idrive controller and the interface responding grows to a laughable 5-10 seconds. Note that this is in the MMI menu before the phone is even connected, so it is absolutely not a CarPlay issue.
- Also when starting the car up in the morning, the MMI interface only appears about half the time. This is easy to fix by holding the menu button for 5 seconds to switch the interface manually, but it is an extra step and it is weird that it is random.
- Audio quality is just a little sub-par. At first I thought I was imagining it, but then I A-B tested the same song played through MMI vs directly through Aux-In and there is a perceptible difference. I'm not sure if this is because of CarPlay or the MMI.
- The unit does respond to steering-wheel controls, but it does not block idrive from also responding to steering-wheel controls. This means that while playing music through carplay, pressing the voice or phone button will activate both Siri and the idrive assistant.
- The steering-wheel track buttons work, but there is about a 3 second delay before the track changes. Also, the directions are backwards from what I would expect.
- The unit seems to stay on with bluetooth enabled about 15 minutes after the car is turned off. This is an issue because sometimes I will turn off the car, get out, go upstairs and my phone is still connected to the car. If I receive a call, I have to manually switch my phone off bluetooth audio.
- With multiple phones paired, I haven't found a way to switch which phone is connected.
- While putting the car in reverse does switch away from the MMI interface, pushing the button to activate 360 view does not.
I spoke with BimmerTech support about this issue. After testing and fiddling with some of the system settings, they ended up sending me a replacement unit. After installing the new unit, I encountered the exact same behavior. This leads me to believe it is not a hardware problem.