Overall, I like my 2009 DTS. It has a good warranty coverage and is a good riding car. I traded in a 2000 Deville for this 2009 DTS. Quality of interior material of my 2009 DTS, although good, is a step down from the quality of material in the 2000 Deville. My 2009 DTS cabin is not as quiet as was the 2000 Deville. Front headrests in the 2009 DTS are rigid, positioned awkwardly, and obstructs rear view when backing up. 2009 DTS gas mileage is poor and the bucket seats are not comfortable for a big man. Other than the aforementioned issues, everything else seems to be okay.
Some of the feature controls (headlights switch, etc.) are half hidden behind the steering wheel. Position all controls in plain view. Provide headrests that can be adjusted (swivel headrest back) to prevent it from pushing the head forward.