I had a luxury rental reservation in IAH this past June. I arrived late because of weather. I was an Emerald member and the woman from the counter took the escalator with me up to the deck, and just pointed at a group of Cadillacs and asked which one I wanted. I went with the pearl white, new DTS with nav system and cooled/heated seats. They had more SRX SUV's, but I wanted the big sedan, as the company was paying. They probably had 1 DTS, 4 SRX, and 3 CTS if I recall correctly.
I miss the "magic" code.