2011 Golf wagon - battery drain issue with new head unit

[ThinkPad79]

Hi there, thanks for having me. I have a 2011 Golf wagon and was given an android/carplay compatible headunit for my birthday (thanks Dad!). The unit is this one: Attention Required! | Cloudflare

Anyway, installation was easy and it worked well but it became apparent that it was draining my battery overnight. I have seen people talking about this issue in pre-2009 model VWs, but mine is a 2011 model so I'm not sure what to make of it. I wonder if anyone can offer any insight. The company who supplied the unit is being vague and unhelpful.

Many thanks for your collective wisdom

[Crasher]

If it is plug and play then there must be a CAN BUS adapter but there are no details.

[ThinkPad79]

If it is plug and play then there must be a CAN BUS adapter but there are no details.

They do sell a CAN BUS adaptor separately (Attention Required! | Cloudflare), but it was unclear to me whether it was required for my car.

Last night I unplugged the new unit and the battery still appeared to drain overnight (not fully, car was slow to start this morning). Maybe it was just already not very charged from the day before going totally flat though ... I'm not sure. I am going to plug the old/factory stereo back in for 24 hours and see what happens, just in case the battery drain is a whole separate issue.

Thanks for your reply, I appreciate it.

[Crasher]

You can’t put an aftermarket head unit in a Golf 5 onwards without using a CAN BUS adapter to provide it with the ignition on signal level command.

[ThinkPad79]

Sorry, I wasn't very clear. It does come with a canbus adaptor but they also sell a separate one, linked above. Using the thing it shipped with doesn't seem to prevent battery drain, so I guess I need the extra one instead/also. Frustratingly I haven't been able to get a clear answer from the company... but my car started normally this morning with the old unit in place, so I assume this is the problem.

Thanks again for your help