Ya, Rex's mod is pretty much done but he's still looking for bugs and glitches before any beta release. Another Thing with his racing mod, is that he uses Checkpoints which use cylinder collision, this method doesnt seem to be proper as a checkpoint for the reason that adding too much collision in a huge area will make the sides further than the middle area. He already tried to code an actor that can just trace the player to send the information that the player touched a checkpoint but his code didnt work well I think. Until he figures out a way to make a perfectly plane checkpoint maybe by using a brush or a trace, the mod will stay unfinished.
I tested his mod since he started it the first minute Rex had the idea, ever since we've made mayor progress in the new gametype and a lot of new things were added. Since there hasnt been a racing gametype for UT, it has been very difficult and hard to figure out how to make it work correctly, but as it is now with the cylinder checkpoints, it is 100% playable and hella fun.
btw, Rex's racing mod doesn't have its own vehicles, at the moment it works with vehicle mods like: SLV, RocketX, QJet, or any projectile based vehicles made for UT. If someone wants to make and code the vehicles for this gametype will have to talk to Rex. I am betting that new ground vehicles will make it very fun and maybe even popular.