I have an 06 STS in Infrared with the Cashmere interior. As delivered, all was nice except the cheesy floor mats. The interior was too bland for my taste (mono-chromatic cashmere), especially since Cadillace trims Cashmere interiors with "light" wood.
I just got my U.S. SPEED Burgundy double-embroidered (Cadillac crest with "STS" in cashmere-matching thread) floor mats.
Beautiful! They liven up the interior just as I expected. And they are so much plusher than the OEM mats. Great job, U.S. SPEED!