D4 Valet mode?

[Saff]

Hi all.

Since getting this car I've never been able to open the boot lid using the key fob. The boot handle and the interior switch both work fine but I cannot open the lid remotely. It kind of negates the advantage of a power lid. Anyway I've googled this and all info tends to point toward a valet switch in the glove box but for the life of me I cannot find one. There is, of course the MMI options but this seems to be to enable/disable the boot handle and does not affect the remote non-function. Neither of my keys work for this. The rear lights (or is it the indicators) flicker while the key is operated (5+ seconds) so there is obviously a signal.
Does anyone have a fix/pointer for this please?

Cheers Steve.