It appears there is a 25% midweek discount going on on the Sixt website.
Used it for an upcoming reservation and got an XCAR for $328 all-out for 3 days! Crossing my fingers for a V90!
I'm in the Emerald Club with National, but $400+ for an FCAR was too much, so Sixt it is!
I'll report on any fleet sightings I see when I pick up!