I installed a set of MSS myself on my G42 which is a little bit more complicated due to Xdrive, but still a very straight forward process.
I'm not entirely sure I'd recommend MSS at this stage though I'm trying to get some communication going with their support team, I'll see how I get to and provide a full review now I've been running the springs for almost 9 months.
I'll also be lowering my G87 when it arrives.
Install:
https://youtu.be/1BITbpvoc00
Results:
https://youtu.be/uopZDgwBFmc