Best place to buy RNS-E units and parts...

Just trying to see where members have gotten their units and parts... from reading the forums it seems many people get their parts from:

- Euro-Parts in the States
(http://www.euro-parts.us/ )
- Kufatec in Germany
(http://shop.kufatec.de/index.php?osCsid=31174d7ee3095d0812fdde4af554e10f)
- classifieds
(http://www.navplus.us/forum/viewforum.php?f=11)

I have looked on ebay for RNS-E units, but theres not a lot of them out there. I am looking for a used

4B0 035 192 P Audi A6 Europe, C5 and Allroad OR
4B0 035 192 R Audi A6 North America, C5 and Allroad

for my 2001 A4 B5. Has anyone had any success outside of the forums and ebay? I tried to contact some salvage yards but no one has any units.