Hey, great to hear you got yours in. Mine is plenty loud with the RCA connections, but I used two RCA's to the Front Channel which goes to the connections on the Factory Amp that powers the doors. I did not use Rear Channel at all, I used the Subwoofer RCA's for the subs powered also by the Factory Amp. I turned OFF the Head Unit's Amp since I ran no speakers from the powered speaker outputs of the Head Unit itself. My Antenna and Wiring harness came from ebay, about $6 or $7 each included shipping. The were the ones recommended several times on this site, parts numbers for VWs, have to look those up. The REAR VIEW CAMERA came from ebay, Sunvalleytek International Inc. It was a total of $18 and change which also included shipping. Have not tried it yet, but it came pretty quick and looks good in the package. all cables included also. Good luck with all this, I'm loving mine (Kenwood 901BT) but can't wait to get the REAR VIEW CAMERA installed. I still have to figuire out about the parking brake sensor and reverse gear sensor... I would like to cheat the system so I can have the camera and video turned on when I want. Let me know if you have any info on that.
Let me know how yours is doing. Later.