Hey Steven
Just to satisfy your curiosity
(and mine) here is the list of all 14 right mirrors glasses that were fitted to the C5 RS6. This does not include mirror glasses that were available in different colours, sizes and specifications for other C5 A6 models. That really would be a rabbit hole I do not wish to travel
8D0857536AC - Mirror glass (flat)
8D0857536AS - Mirror glass (flat)
8D0857536AD - Mirror glass (convex)
8D0857536AT - Mirror glass (convex)
8D0857536AE - Mirror glass (aspherical-wide angle)
8D0857536BA - Mirror glass (aspherical-wide angle)
8D0857536F - Mirror glass (flat) * automatic anti-dazzle
8D0857536BD - Mirror glass (flat) * automatic anti-dazzle
8D0857536G - Mirror glass (convex) * automatic anti-dazzle
8D0857536BE - Mirror glass (convex) * automatic anti-dazzle
8D0857536H - Mirror glass (aspherical-wide angle) * automatic anti-dazzle
8D0857536BF - Mirror glass (aspherical-wide angle) * automatic anti-dazzle
8D0857536AF - Mirror glass (convex) (Arabic writing) 175x100mm
8D0857536BB - Mirror glass (convex) (Arabic writing) 175x100mm
It's the same situation with the left-hand mirror glass, many variants for C5 RS6.
Have a nice weekend
Regards
Craig Barlow
Daytona RS6 C5 Avant. BRV Plus Engine, 550cc Injectors, Custom Tune, DO88 Silicone Pipework, Waggers, Hybrid Turbos, Direnza DownPipes with 200 CEL CATS, Milltek Exhaust, Sonnax Modified Valve Body, Uprated Clutches, Uprated Torque Convertor, R8 Carbon Ceramics, K&W v1, Exclusive Interior, Creations Motorsport Billet Coolant Cap and PCV Valve (woohoo)