Built from `2002` to `2004`, the `RS 6 C5` saloon applied the `RS` estate formula to a much more discreet executive body that was just as serious underneath. Against a highly powered BMW 5 Series or Mercedes-Benz E-Class, it already offered a modern super-saloon recipe: twin-turbo `V8`, four-wheel drive and genuinely high top-end speed. On the used market its rarity helps, but the technical complexity rules out any romantic purchase.
At the centre is the `4.2 V8 biturbo BCY` with `tiptronic` and `quattro`, backed up by `DRC` on the chassis. The whole question is whether the car received what it needs: full timing-belt work, faultless cooling, healthy turbos, a respected gearbox, suspension restored properly and engine ancillaries dealt with before failure. On an `RS 6 C5`, even a small maintenance shortcut turns into a heavy invoice very quickly.