Dryseals, yeah, Australian Raven as canonrock indicated. I can't help but laugh when I hear them, especially the ones that sound like a very adenoidal yet somehow very blase child being strangled. Hope you also got to hear Aussie Magpies in their dawn chorus, a truly heavenly sound. Someone described them as the sound of angels gargling.
LOL on the grackle description. Colonelboris, that's a Great-tailed Grackle shown in the pic, but the description is also apt for Florida's Boat-tailed Grackle, a close relative. The most widespread species, the Common Grackle, doesn't seem to hang out in fast-food carparks as much. All are members of the New World Icterid family.