I took a chance on some black mirror caps from a Chinese distributor on Ebay (
http://www.ebay.com/itm/272503042309). They were so cheap I figured why not give it a shot.
From super close you can see some of the molding lines
Fitment was near perfect. Took a couple minutes of fidgeting to get it on flush, but once it snapped on it was fine.
From a realistic distance if I didn't know better I wouldn't think they weren't OEM.
I also tossed these on and they're absolutely amazing
https://www.becautoparts.com/products/vw-mk7-golf-gti-blue-tint-aspherical-mirrors. I already had my mirrors lined up for blind spots
But I still found myself wanting to turn my head for reassurance. These mirrors provide such a wide angle that I feel like I can see everything around my car with confidence.