On a whim last weekend, I registered for the Crystal City Diamond Derby, the first race I’ve done in a while. (Placed 7th!) The race’s combination of scavenger hunt elements and its underground setting reminded me of a few other race ideas I’ve thought of in the past. A lot of the riders seemed unclear on the concept; I watched them fly past the bonus-point checkpoints, which were where I got probably 3/4 of my points.
I did find one photo (Andy Zalan) and one video (by Mark Blacknell, see about 1:00 – 1:40) of me riding.
west north 
Wasn’t just a great time, but a great idea for the weekend use of garages like that. Perfectly replicable across cities.
(And yes, I completely missed half the checkpoints. Never heard the starting instructions, and by the time I clued in on it, hey, I was just having a grand time going fast in a garage :D)
They hinted at the instructions in the written description, which mentioned something about “collecting diamonds.” I’m glad I did stop at all of them, since my “racing” involved way too much completely unnecessary stopping, or near-stopping — for curves, dismounts, whatever. Shoulda prepped for that running dismount.
I’ve wanted to run a race in an aboveground garage for a while. There aren’t many around, but the recent Bike Snob welcome ride treated everyone to the view from Nats Park.