It was luring to make the kart track of Ahvenisto fully functional and I couldn't resist.
Install: make sure your "Ahvenisto Race Circuit" is working and then add this layout by placing the contents of the .7z in "..\content\tracks\" folder of the game. Confirm merging of folders. All seasonal and lighting changes are from the specific "..\content\tracks\ahvenisto_rc\kart_long\extension\ext_config.ini" so they don't affect the other layouts unless you choose to edit the contents yourself.
Happy driving!
Install: make sure your "Ahvenisto Race Circuit" is working and then add this layout by placing the contents of the .7z in "..\content\tracks\" folder of the game. Confirm merging of folders. All seasonal and lighting changes are from the specific "..\content\tracks\ahvenisto_rc\kart_long\extension\ext_config.ini" so they don't affect the other layouts unless you choose to edit the contents yourself.
Happy driving!