Let's say we're first at a 4-way so it's our right-of-way going straight with a car with tinted windows such that we can't see the driver's eyes. Do we proceed as normal only assuming that the driver sees us? Do we refuse to proceed thus potentially wasting both parties times?
I have done the latter with a motion with my two fingers pointing to my two eyes, then at the drivers with a shrug - trying to convey the message "I can't see your eyes". Is there a better "international symbol/gesture" that conveys this message? Or should I just turn right? : )