In the Mesh Modeler, I discovered that moving the spawn position (light blue square) far away from the trigger (green square) resulted in a block that teleports a vehicle. To activate the teleportation, pass through the trigger, then press the button assigned to the "respawn" function.

In this example, I changed the Z coordinate of the spawn position of an ordinary Stadium road checkpoint block to 315.

Instructions:

1. Extract the Gbx file in the zip file to:
%USERPROFILE%\Documents\ManiaPlanet\Blocks\Stadium\
2. Create or open a Stadium map.
3. Navigate to folder 1-2. Notice how block 1-2-1 now has a folder surrounding its icon.
4. Click on the variant with the smaller, darker icon inside this folder to place this custom block on your map.

I hope this custom block inspires people to invent their own teleportation blocks.