Not sure why they would say such a thing - as long as you have the right one (year & rain sensor) they have the same mount (same with A5), and there's plenty of room - in fact the car NEEDS the bigger mirror IMHO. The mirror I'm comparing though is from a Subaru, so it has the compass AND HomeLink both in it. The mount on that unit IS different (as is the color of the compass letters), but only from the gimbel to the Audi mount, and I'm digging into how to fix that part now ...cuz the HomeLink mirrors with compass for Subarus, Kias and Hyundais are usually available for $50-80, compared with the Audi versions of the same basic Gentex mirror for $2-300.