I don't believe it is the wiring because most of this will have been designed for the car; however, the CAN-bus system is adapted (due to the significant cost to develop a full system from new) and therefore, as with certain other anomalies, I wonder if the system isn't shutting down all the items that would/could drain power?
As for the light in the boot that people have questioned whether or not it stays on, wouldn't a solution be to put a switch in line between the power source and the light? If switching the light off (manually) stops the drain, then problem solved. Pulling the bulb would also (I believe) have the same effect but does leave the socket live.
That is my 2p
