12V Boot Socket
This 12V socket is available from www.vagparts.com for around £20 and is an Audi Part though I am not sure which Audi it comes in as standard.
The socket itself is very deep installation is simple by having to cut a hole to mount it but locations are limited.
Remove the boot trim panel
The panel space behind the trim is very tight, the only space I could find was either on the door for the light cluster or further forward nearer the seat back.
A couple of spade connectors and a wire rated at least capable of 10A should be used the other end should be tapped into a power feed from the fuse box, I already had a feed for my PS2 to tap into.
Although hidden in my install the finished article looks really good and will hopefully come in useful next time we want to use the cooler on a outing.