I've had three DRC failures -- at 32K mi, 50K and 74K mi. First two fixed under new car warranty; last one covered by Fidelity. My experience was that they covered it as long as I stayed on top of them, and referring to page 42 in the RS 6 Self Study Guide published by AOA helped; that's where the requirement for the central valve accumulator's mandatory replacement is shown. Assume nothing; see link.
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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