"the wiring loom in a 2017 conventional petrol or diesel car is one of the most expensive components"
That made me think of my own adventure in car repair.
The car was a 1986 D Mark II Fiesta, with the 1.1L petrol engine. I bought it in 1995 when I got a better job and (a) could afford to buy a car and (b) needed to buy one to get to the job and (c) even had more money after paying for the car in the new job than I had had without the car in the old one.
In around 1997-8, the sticky-out bits on the ends of the wiring to the right-hand front indicator bulb housing broke off, so there was nothing to hold the wiring in place.
Ford service manager: Hmm. Well, that housing is actually part of the wiring loom - it's not meant to be replaced separately.
Steve: How much would that cost to replace?
Manager: About 500 quid just for a new wiring loom and ... a lot ... for the labour to replace it.
Steve: (hard look) Just to replace the bulb housing?
Manager: Let me talk to the lads in the back.
Manager: Good news. If you go to the Ford Truck and Van Repair Centre at (gives directions) you can get a spare housing for a Transit - it's mechanically compatible with the socket for the housing - and splice some spade connectors onto the existing wires to connect it up.
Steve: Cool, thanks.
FT&VRC sales attendant: That'll be eight ninety five, thanks.
Yeah, from half a grand plus labour to under a tenner. I'll take that.