I had terrible luck at BWI Exec on March 31 (a Monday) at 5pm. I was lucky to get an regular Grand Prix.... and I was really looking for a Trailblazer LS as I had about seven hours of driving over three days. I asked if I could take one of the premium cars (I think a 300) in the extra-special spot right outside the entrance, and was curtly told that those were not EA cars.
OTOH, they were charging $78/day, and I was using up three free days rather than pay that kind of money, so I can't complain too terribly much.