My 8" screen just came in the mail today that I purchased on eBay for $498 with shipping. Its from Taiwan. It came with its own navigation but I just stuck with the Becker unit I already have. It was just unscrew and plug n play took only 5 mins. Everything works. Phone, back up cam, navigation, etc.
All the know is the touch isn't that responsive because these are the basic units with no mirroring. The touch doesn't work at all with the default MB software. The custom navigation works but I haven't played with it yet.
I think these are units from carnavitech. The better units are from navitech from korea. But unfortunately those guys didnt respond to my email for purchase so I just took the chance with these Taiwanese ones from ebay.
Just ordered myself one of these with AirPlay Mirroring and a front camera. Tried contacting the company in Asia but they weren't very responsive and didn't seem legit. Found a place in Australia that seems much better. I should be getting it soon.