That's literally what happens! When I was in my dispute with ERAC over the damage claim last spring I went to Budget at YYZ, whereas National had 5.0 Mustang convertibles or, at the very least, a brand new Fusion with less than 1,000 km on it available. I went to Budget and got a Yaris Sedan for my Compact (Focus or similar) booking.

That being said, lately there's always been at least one Sonata or Fusion kicking around, so I've never left disappointed really. Just would've liked to try out the Sport model or one of the Passats, which always seem to show up as I'm RETURNING...