Does it matter which way the magnets go in on a pancake motor?
I have a red one and a white one. Not sure which way they go back in.
As long as they are opposite polarity (attract to each other) they will work but if you put them in backwards, the car will go the wrong way. If that happens, just take them out, swap them around and you will be good to go.
Because of the extra gear the 4 gear cars need to have the magnets installed opposite of the way they go in the 3 gear pancakes.