That's an interesting perspective. From my personal experience, the few 204 C63s I've had have seemed well screwed together. And the w212s I've been in have always seemed decently built. But no denying the RS6 interior is streets ahead in terms of styling... Those seats are lush. Makes the 212 E63 feel very 'granddad' in comparison lol.I would suggest that the additional cost on the Audi is worth if for the superior build quality alone. I've never owned an RS6 (more's the pity) but I have owned 3 other Audi's and they are extremely well put together, way better than anything else i've ever owned. If £20k more got me a rattle free interior made from high quality materials I could justify it.