I have a trickle charger that lives in the boot, but the car is outside.
I have fitted an outdoor socket to the house but I still needed to get electric into the boot.
Me being me didn't like plan A which was to shut the cable in the boot and leave it trailing...
So plan B was hatched...
Connected (All externals sealed to IP65!):

Free socket:

Car inlet:

Inlet capped:

Internal socket so the trickle charger can be removed:

Trickle charger:

Back of inlet (Yes it's a spark plug boot but it fit nicely!):

Rich