Well, I noticed your emphasis on fuel consumption and reliability. You may opt for an Acura or Lexus in this case, especially as the latter (IS350) comes close to the 3-series in terms of competence. The only problem with the IS is that it doesn't perform great beyond 8/10ths driving and of course, doesn't have the chassis communication (then again, what does?). The Acura TSX is a terrific choice from Honda, with solid reliability and a good chassis. A terrific front-drive choice that handles very well. It's just a bit short on muscle. Don't bother with the TL; it's just an Accord that has too much power going to the wrong wheels that is about as Japanese as the California Roll.

CPO E90s are not cheap at this point, and the first MY had its own set of bugs. Plus you dont have a dipstick, and everything is computer sensor-dependent, which IMO can lead to problems down the road. The E46 convertible is a terrific vehicle and my preferred cabrio. It is also fairly reliable, for a BMW. No reason not to get one, but I don't know how "reliable" it must be. I mean, the automatic gearbox is going to go at 100k miles regardless of what BMW you buy.

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2014 Mazda 3 GT: Ø Consumption: (click for details)