Do you want full surround, L,R & sub.... Floor standers or bookshelf...
Just avoid cheap makes and get the best you can afford, and don't skimp on wiring and cables
Does it only warn you when you are going faster than the camera allows
Thats what my aftermarket one does, if you are a good boy she is quiet, if you push it a bit to hard she complains.... Oh no hang on thats the misses not the satnav
Have to say me either, ok I have had a few 'incidents' in the Zed but I have done over 40k
I think it is down to the persons driving style as to how others behave around them