"R.C. Payne" gurgled happily, sounding much like they were saying:
I was thinking more in terms of the vehicles we were discussing in this thread - cars and light vans.
Trolley buses and railway vehicles are significantly different, in that they don't store the electrickery on board - and have a much, much higher initial purchase cost than a Ford Focus. Because of that, they're typically refitted several times over a working life - diesel or electric.