BBQ C2 is the only stand-alone Carmageddon 2 installation made to play against eachother. It runs best on LAN (even on modern systems) but can also work over the Internet via vLAN, direct connection or through a master server (most cases require a very high connection speed though).
Mayan Mayhem was a C1 race. It was ported to C2 and BBQ as a night time track.