G'day Roger,
I have a Edge here in Canada, I installed the Pioneer AVIC-D3 Navigation system (current equlivent AVIC-F900BT) in mine just after I got. You can get the brackets and plates and cables from places like www.crutchfields.com and ebay. And with PAC SWI-PS you can use all the buttons on the steering wheel. Any two DIN unit will fit, and the installation (with the exception of the light dimmer) is all pretty easy.
I have a question for you.... Does the Swiss model have amber (orange) rear turn signals? or are they the standard Nth American red?
Regards
CD