Ok, so I know it's bordering on sacreligious, but I need to fit a tow bar to my x300.

I'm looking at fitting a "removable" or "retractable" type, as I would use it only very occasionally and would like not to spoil the look of the car on a permanent basis.
My question however, is about the trailer board, that board with the tail lights attached which plugs into the socket that is fitted to the tow bar.

I am curious to know if there is a handy/convenient/ready made point within the boot where the power lead can be spliced into, or better still, a way to connect it via a plug of sorts in the boot, so the power cable can be removed with the tow bar.

Maybe another plug and socket arrangement in the boot? Will the extra lights play any games with the ECU, given how fussy they seem to be about changes from the factory set norm? I have the wiring diagrams, so identifying the relevant wires shouldn't be a issue. Just wondered had anyone done this before.

Many thanks