The Lionel 3376 Bronx Zoo ducking Giraffe car is the most kid pleasing car I have. They really enjoy seeing a string of 5 or 6 giraffe cars in a row duck their heads and pop back up in sequence when going under a bridge or tunnel.
The Lionel Giraffe car is easy to find, cheap to buy, easy to rig up a rail to trip the ducking lever and very reliable. It is very simple and has no switches or solenoids to miss with.
What car is the favorite of the kids visiting your lay?
Charlie