I do, and it is useful...cool to play tunes through the stereo from other devices with it as well as charging. I've used the original with an iphone and got connection, and used the USB style (real VW part, about that $37 price also) with a flash drive, SD card with adapter and a Sansa 240 MP3 player. It acts as a second SD card this way, effectively doubling your tune capacity.
The system isn't brilliantly quick, sometimes it loads as fast as the SD card or it will take many minutes to communicate, and you won't always know if it is comming online or not. Unawesomely it is hooked into the ignition like the 12vdc sockets, so each engine start throws two blips of power and data through the line and I think it gets confused.
Flash is my preference. It doesn't compete/contain energy, and the SD card/adapter through this USD cable is unstable (bumps can cause it to reinitiialize repeatedly.) I even wrap the flash drive in foam. The MP3 player charges only with the ignition like the 12V which is another step for it to deal with as stated, not to mention it has it's own initiation sequence....
And for best results I think one should really only plug things in after the motor is running and unplug it again before you shut it off for the above reason, which is a hassle no one could tolerate. Don't get me wrong, the amenity is fantastic, just giving you my real world experience caveats.
I wouldn't charge more that one thing from it at a time check
rockatship, that's for sure! For that stuff you can't beat a dedicated fused power line from the battery hooked into your own switched-DC-charging-ports. There are many fine products at a variety of retailers near you.
