Whisper vroom

Interesting day at the Frankfurt Motor Show press preview. There are more electric cars here than I can recall at any previous international motor show.
This is the amazing Mercedes-Benz show hall - they're too grand for just a stand - and on entry a vast escalator whisks you right to the top of the building.
To exit, they make you walk all the way down long staircases, and past every display car. What a cunning ploy!