When it comes to luxury sedans, the 2007 Cadillac STS has stepped up its game with more trims and standard 6 speed automatic transmission on all its V8 trims. In addition, all trims with OnStar will get Turn-by-Turn Navigation that connects you to a live advisor to get you where you need to go. The 2007 STS comes in 7 trims: the V, V6, V6 Luxury, V6 Luxury Performance, V8 Luxury, V8 Luxury Performance, and V8 Premium Luxury Performance. V6's use a 3.6 L, 255 hp engine, the V8's use a 4.6 L, 320 hp engine, and the V has a 4.6 L, 469 hp engine. The V6 and V8 trims get you around 17 mpg in the city, 26 on the highway while the V gets you 14 mpg city/21 mpg. All trims have 4 doors and seat 5. Overall, reviewers like the Cadillac STS' handling and performance. You can't go wrong with V6 trims, although most people would recommend getting the stronger V8. In addition, drivers like the interior and exterior design. Despite some pricy options, Cadillac has come up with another hit that continues to evolve over time.