Originally posted by: InflatableBuddha
Reliability breakdown, in general:
Lexus = excellent
Acura = excellent (exception: early 2000's CL)
Porsche = very good
Mercedes, BMW (except the 3-Series), Audi = below average
Jaguar = terrible
Luxury cars cost more largely because they contain extra, more sophisticated equipment (premium sound systems, leather, extra airbags, navigation, TCS, etc). As well, the engines are larger and more refined.
All of these features are only good value, though, if the car is reliable and doesn't cost a small fortune for repairs. I think you get good value for Lexus, Acura and Porsche. For the other marques, you're paying extra for the brand worth - i.e. BMWs have awesome handling and stunning interiors, but for the high price, you should get stronger engines and better reliability.