I liked the Stackable Slotcar Stand by Krpepe but it did not work properly for other car brands like RevoSlot, Slot.it or any other with different magnet position, no magnets ;) or different guide sizes/length.

Therefor I adjusted the version with a more flexible and longer guide rail. I also added additional holes for the magnets, but also designed a small strut which can be put into the wholes instead of the magnets to avoid the car to flip over.

Depending on your printer you need to shrink or extend the struts, or use a drill ;)