Hi and welcome.
another e53 owner here.
the Pdc is a right pain, get a copy of pa soft and a laptop and scan, it’s a money saver and a nerve saver!
by scanning for any issues, it will pinpoint which sensors are causing issues. Once one goes, it throws the whole system out. Another way is to put the car in reverse (without the engine running!!!!) and put your ear to each sensor. You should hear it click. The one(s) which doesn’t clock is the issue.
The stereos are all pretty similar in the xtronnproce range. I have one and it does the job.
I have sat nav, reversing camera , as card, cd, radio, Bluetooth etc and steering wheel controls too.
there are higher end ones that will retain the dash signals .IE the time etc on the dash, but I just use the time on the head unit. The dash tells me how rapidly I run out of petrol ( currently 17mpg average)
If your problems are only the ones listed above… get ready! Haha.
I have also had a couple of bm’s
e30 318 coupe, e36 316 saloon x2, e34 518,520,525, e46 316, e90 2.0, e53 3.0 …