That is really nice how much did it cost and what does it have? Bluetooth iPod dab ?
There are two versions of the RCD 330G and they all use the Quadlock interface so is a straight swap on the MK5 Golf's. The standard version comes with a 5.0" touchscreen, refreshed MIB Interface of the newer MK7 Golfs, CD Player, FM/AM Radio (No DAB I'm afraid), AUX, SD Card Reader, USB/iPod connectivity, MirrorLink, OPS and Reverse Camera Support* (with 3rd party camera module), built in Bluetooth (telephony and A2DP audio streaming) and Microphone in one unit. You can get these units for about £90-£120 on AliExpress depending on exchange rates.
The RCD 330G Plus shares the same features as above but omits the CD Player in place of a larger screen (6.5") which in my opinion is very sharp and easy on the eyes, plus it makes it a bit easier to tap the menus on the screen too! The RCD 330G Plus costed me £180 all in including delivery from a seller on AliExpress. Shipping was very quick, literally took just 3 days from their base in China straight to the dashboard of my GTI!
There's no Sat Nav on these but I haven't had the chance to try out the Mirrorlink function as my current phone don't support this feature. Basically it copies the interface of your smartphone straight to the stereo screen so theoretically you can run various apps like navigation and car telemetry data on it which can be pretty cool if you can get it working.
any issues with fitting this to an older car in terms of canbus and bat drain? they are new 2016 headunits AFAIK are they?
They are the new 2016 units so most likely you will need a new Canbus Gateway (ideally a 7K0 907 530) to avoid battery drain. I'm running an updated 7K0 907 530AM gateway on my 2005 GTI and they're not expensive to get these days. There have been reports of the MK5 multifunction steering wheel controls not working on the basic RCN 210 stereo it's probably be true on the higher RCD 330G units too where you need the updated CH steering module to solve the problem (I don't have a MFSW so can't confirm this as yet).
Still I only had it for a day but I will keep you guys posted on the experiences and quirks to see if it's a worthy OEM alternative to the RCD 510 and others.