It's not just the Axis-Vegas models, it's all brands and models that have the reflection problem at night. I've searched quite a bit, but have not found a good solution. I hope you fair better, and if you find a good solution, please post. Good luck.
Yes, after doing some searching, it seems that it is a universal problem with viewing the rear mirrors thru flat windows. One solution is found over on the irv2 forum where a guy mounted a black sheet at an angle to block the reflection in the area of the flat window used for viewing the mirror. Hard to describe, but below is a link with pics. I think I will try it as it is simple and inexpensive.