The STS started out as an up-level trim of the midsized Seville, with a strong 4.6-liter V8, traction control, and an active suspension system.
The STS accelerated faster than many of the performance cars of its day and even carved relatively crisp corners.
However, in exchange for the better than average handling, it didn't ride particularly well.
For 2005, Cadillac renamed the Seville the STS and switched to rear- or all-wheel drive, turning it into a genuinely competitive sports sedan.
Power came from a 255-hp V6 or an ultra smooth 320-hp V8.
The ride is firm but supple.
The car is fun to drive and handles well, but rear-seat room is relatively tight and the interior doesn't measure up.
The STS-V is a quicker supercharged version.
Model year 2008 brought a 3.6-liter V6 as well as a few interior updates and 2011 was the final year.