Regarding Dub Coaster: I tested it yesterday and everything was working, including the teleport CPs :/.
And now, after over 3 years, my latest (14th) map: Speedbowl (3 Laps)! It's mostly based on "Speedbowl" from FlatOut 2:
Demo video of the map:
Map download attached.
NOTE TO WHOEVER UPLOADS IT: Please disable ghostmode after 5 CPs like other race maps.