With US cars, features are tied to the trim level and while anything is technically possible, there are hard ways and easy ways to get what you want. We have a 2014 EOS in the Komfort trim. I still have the 2014 sales brochure and I consulted it for the following info.
Neither the Komfort trim or the Sport trim came standard with autodimming mirrors of any sort. Your only option is to retrofit them. The easiest method to do that is with a Gentex rearview retrofit which is easy and affordable. There is no easy way to retrofit the outside autodimming mirrors unless you want to spring for a windshield replacement (or the aggressive technique that Vox linked to), the RLS sensor and some extra wiring, not to mention the mirrors themselves. Then there's the coding, etc... Going for external autodimming on a Komfort or a Sport trim is probably going to set you back a LOT financially. Note that the Komfort was the most common trim sold here mainly because it was the most affordable.
Or... You could buy a Executive Trim car that came standard with the correct windshield, the RLS sensor, the inside autodimming mirror AND an external autodimming mirror on the drivers side only. Most folks would probably stop here, but with some wiring and coding you could probably add an autodimming passenger side mirror as well. Keep in mind that the 2014 Executive trim stickered for $40k, so many fewer of those were sold. I dare say most were probably ordered because finding one on a lot was not easy.
VW changed things up quite a bit year to year throughout the EOS's run, but generally the higher the trim, the more likely that some of the components needed for autodimming mirrors might already be present. Some components started out on the higher trims only and gradually moved down to the lower trims during the model run. The best example I can think of is the Nav Radio. Early on you couldn't get it on a Komfort, but by 2014 it came standard on that trim. The same is probably true for a glove box light. I'm guessing that Autodimming mirrors may have only ever been on the highest trim line. The EOS was incredibly expensive for a VW and adding the features that we might take for granted these days was unheard of back then because of price creep. My wife had a 2012 VW Tiguan SEL w/Premium Nav that we bought new ($39k sticker) and back then the only autodimming item was that high-end trim and that was for internal only.
