Self-guided car in my city

[DKW]

Hi all, I’m looking for some help please!

I’d like to add more movement to my Lego city and have seen the self-driving cars that travel round the displays in Legoland.

I have found a couple of ideas online that utilise a metal wire placed under the base plate which guide a magnet on the underside of the vehicle. 
 

My question is how can I make the smallest motor to add to a vehicle? I’ve got various power function motors, battery packs etc but struggling to think of a way to put it all together so it doesn’t end up being completely out of scale for the rest of my city. 
 

any ideas and suggestions would be gratefully appreciated.

[JopieK]

Maybe you should look into Curcuit cube (it is not LEGO, but compatible). Faller e.g. uses wires and a magnet to steer the wheels.

[jus1973]

12 hours ago, JopieK said:

Maybe you should look into Curcuit cube (it is not LEGO, but compatible). Faller e.g. uses wires and a magnet to steer the wheels.

I like those Curcuit Cubes.  Never seen them before, and if they weren’t so expensive I would love to add them into my developing town. 

[Jeroen vW]

There is a way to include smal N20 motors.

https://www.youtube.com/watch?v=-yAbtxD6Sa4. You don't need the 'box' of the design that goes over the motor. Only the plate that goes in front.

Or you could do it with this one

https://www.thingiverse.com/thing:3968044

Maybe you could do the same for even smaller motors.

Kind regards.

Jeroen