Given that, I'd opt for the M3. Or, if you have your heart set on getting a car that always will be rare, look for an RS6 elsewhere. Some markets are pricier than others; dealers vary too. When I recently scrolled through available RS6s at cars.com, a few at the top were in the absurd range, but then prices mostly settled into a range of mid 30s to low 40s.

I realize the RS6 will depreciate -- especially if you pay $55K for one! But the mid-30s to low-40s range has been around for months. Depreciation has slowed compared to its early years, as with most vehicles.

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Current: 03 RS6 - Mugello blue, carbon fiber, solar package
Previous includes: 05 Crossfire SRT6, 00 S4, 98 A4, 86 Buick Regal turbo, 75 BMW 530i, 7? Lotus Elite, 72 Jaguar XJ6, 71 Audi 100LS, 69 Firebird 400 convertible, 68 Dodge Charger, 52 Triumph TR2