The vast majority of mag steered model vehicles are 1:87 scale. They are used, in many cases, on HO train layouts, which happens to be the most popular train scale. Some HO mag steer vehicles are shown below. These vehicles are part of the large number of items in the Faller Car System. Faller is a German company, so most of the vehicles are German.
Opel Fire Command Suv
Generic Sedan with No Emblems – Looks like a Mercedes to me.
Most of the HO vehicles are trucks or buses. This allows much bigger batteries for longer run times.
The biggest user and most advanced technology in the mag steer world is at ‘Miniatur Wunderland‘ in Hamburg, Germany. They have hundreds of vehicles running, autonomously, on one of the world’s largest 1:87 scale operating dioramas. A scene in the USA section is shown below:
Faller vehicles have a steerable magnet that follows a magnetic wire buried in the road. Unfortunately, the magnet is designed to drag on the road and eventually creates an unrealistic wear spot in the middle of the lane as seen above.