To veer back in the direction of electronics, while not entirely abandoning cars:
I'm planning to add a dashcam to the BMW. In particular I want one with 'parking mode' and that pretty much necessitates hardwiring the dashcam to the car's electrics so that it gets the 'ACC' signal to loosely tell it when the car's being driven or parked and stop me from having to ever manually intervene. That necessitated a hunt for where in the electrical system to pick up the appropriate wires.
Part of the journey to find that information was what led me to trip over the Engineer crimp pliers, one poster doing something similar to me had bought a pair to crimp the contacts BMW use in their power distribution system.
Which leads me to BMW fuse boxes. They have a really neat and tidy system of wiring up fuse boxes that I haven't seen done before. If you know how BMW do this you can stop reading now.
BMW's fuse boxes use the, now ubiquitous, 'continental' blade fuses. On one side of the fuse the blade goes into a permanent two bladed receptacle in the fuse box where it picks up power. On the other blade of the fuse it goes to a two bladed crimp contact that takes the power off to the device/system being fed. The device side contacts are held in plug bodies not dissimilar to Molex type plugs, one plug to [typically] eight fuses, which come into the back of the fusebox. So to add a circuit you simply pick a spare unoccupied fuse slot that is already fed with the kind of power you need (switched with ignition, unswitched and so on). Then you crimp a double bladed contact to your new circuit and push it into the appropriate empty hole in the plug and the job's done.
Pictures from a scrapie on ebay.
Front of fusebox:
Back of fusebox with some plugs in place.
Very neat, I like it.
By dint of good luck BWM supply their own aftermarket dashcam, which I won't be getting as it's ~£500 fitted for something that's on a par with £100-£150 dashcams from other suppliers. BUT, there are fitting instructions available from BMW that even call out the correct spare fuse slots that you should use to supply switched and unswitched power to the dashcam. Nice.