In the dim and distant past my lot hired a Volvo FL10 tractor unit for me to run the night trunk with, Edit, nope it was an F10 that's put a few more years on me.
Driving across our yard all of a sudden the cab filled with choking fumes, i stopped immediately and got out saw a wire which was glowing red so hit the thing snapping it which stopped the problem, however on closer inspection where that wire ran through the cab wiring loom it had started to melt the loom insulation, lots of it. On even closer inspection i found that some half wit had jerry wired a 12 volt radio in from one battery only, where that errant wire entered the cab via a grommet our hero had fed the wire outside grommet, 'tween grommet and steel cab not through it.
Made me think though if that had happened at 60mph on the motorway by the time you'd stopped the vehicle you could well be overcome by fumes.
Nasty how that RR's gone up, taken the womans kichen out too, you'd try and get it away from the house if it was going up but thats easy to say from the comfort of my chair here.