Tokyo Highway 2 + 4 Kit

From BoardGameGeek:

This is an upgrade kit for 2-player Tokyo Highway (2016) and 4-player Tokyo Highway (2018) to make a 6-player version of Tokyo Highway. Adds 2 extra buildings and sets of 10 green and purple cars. Requires the road and pillar components from the 2-player version and all the components of the 4-player version to play. Or just use as alternative colored cars for your 2-4 players games!