When the Big D inaugurated its D1 route between DCA and LAX, I was attempting to upgrade using RUCs. On the inaugural DCA-LAX, I was #2 for 1 seat 45 minutes before departure when suddenly there were two no shows, and I got one of the upgrade seats. On the way back, I got upgraded at the gate as #2 for 3 seats. I've tried to upgrade with RUCs on four segments on this route since then and went 0 for 4; D1 was sold out days before departure; I was #1 on the UG list on each of the flights and all the reservation holders showed up. If I want to use RUCs on the LAX trips, I have to connect in ATL or MSP.