It seemed like a good idea at the time.....
I wanted to install a couple of USB sockets so I could charge phones and power satnav 'on the go'. The wonderful world of eBay provided me with a unit which had USB sockets, a spare cigar lighter socket, and a volt meter.
These happily sit in the slot where my ash tray goes, with wires to connectors on the fuse board. So far, so good.
But what a distraction the voltmeter is! It is digital, bright blue lights, and constantly feeding me voltage information to the nearest 0.1v. I'm sure it will eventually disappear into my peripheral vision, but for now it is highly entertaining.