I am very happy for you, not for obtaining the Xenons, but that you got Dynaudio which is superb value for money but a pain to retro-fit, though not as difficult as the Xenons. A car without a decent soundsystem is nothing but a taxi IMO. I am glad you changed your car as I know it was touch and go making that decision.
What I'd like to learn from you is whether the RCD510 and the RNS510 sound any different from each other.
With regards to your reversing situation and to provide you with good rear end sensitivity, a most important function, perhaps you should consider a reversing camera. I am not sure, but aftermarket sensors might probably not show up distances on the RNS510 screen. I have both front and rear sensors which I find invaluable, show distances on the RNS510 screen and beep with different tones for front and rear activation from the front and rear loudspeakers respectively.
Soon, very, very soon, it will be my turn to post pictures of my new purchase. I have no choice but to follow suite.
You could name your car Lord Greystoke or Tarzan or even Jane (when you are in the mood). For simplicity, I've named it Tarzan for you: you little swinger!