I have updated my system to V7 6 digit post code and firmware 2680 I think.

In my original radio when reversing the sound of the radio/cd reduced and a display indicated the position of objects.

Is this option available in the RNS510?

Where can I get a Mic for the voice control or can I alter or tap into my Kuftec/Fiscon Blutooth Mic?

The young lady keeps saying "Pardon"

What MY is your car? It is certainly possible to get the sensor display on the Columbus but if yours is a pre-FL then you'll probably need an updated controller for your parking sensors. I have a 2007 and have just retro fitted a Columbus and my parking sensors don't show up visually any more. Would be nice but given the cost and time of getting new controller, I'm happy to just have the beeps!

Can't help with the auto volume reduction but I'm sure someone on here can

As for the Fiscon, I've heard that pardon is quite common with them! But I can't speak from personal experience, so again someone else on here will be better placed to give you more help on that one