Are we just looking to mark the '10th Anniversary' or would a general 'Anniversary Edition' badge be considered.
We all know the current A2 was and is likely to be the only Aluminium version that Audi produced no MkII etc, and we could as proposed mark the occasion with the '10th Anniversary' badge. or
We could mark the 10th Anniversary of the individual A2s from date of first registration hence 'Anniversary Edition'.
Size wise, suggest restricted to the width of the rear A2 badge, as this is a constant across the A2 range.