The convex driver's side outside mirrors are rather a must option
on European delivered cars, not just the BMWs but
the other ones as well, likePeugeot, FIAT and other ones.
The original mirrors look like this:
Int the US we are using little "glue-on" round mirrors that cost about
$1 to $3 a piece and are glued on to the original mirror.
The round convex mirror are not tinted or coated, they are plain white glass
On a BMW this would destroy the upscale look of a vehicle if something cheap like that would be glued onthe mirror - it's like having disposable tableware at a "White Glove" reception.
Of course, the BMW optional heated glass do not come cheap.
On top of that, the BMW dealers in the US will not be able to identify the part numbers
unless they pull the same vehicle in the ETK using the ECE option.