Having spent the day reading all of the great post on here about audio upgrades, I am now clear on a number of things but I wonder if I can ask a couple of specific questions?

I have a 2008 LCI 530D, with the standard spec stereo. I do not have tweeters.
Now that the 555 Amp has been discontinued I have no choice but purchase another make/type. So I have been looking at 5 channel amps. I want to drive all four speakers, with the tweeters driven from the front mids and the 8 in subs driven directly by the amp.

My question is around the wiring for a non 555 PnP amp. Is it just a questions of buying the interfacing harness for the PnP 555 then removing the plugs at the AMP end and manually fixing these to the new amp? My concern is that things like parking sensors and phone will be messed up due to the optical feed. Also how does the remote switch work? I assume the amp will not be on all the time?

Any help, or guidance would be appreciated!