Exactly... you can try to make eye contact, but if you don't, do you still ride?

Of course you do... so the eye contact thing is a good suggestion, but quite often, it is just not possible due to sun glasses, tinted windows, glare, darkness of night or speed. More often than not, we then depend on the rules of the road for drivers of vehicles to be our guide. And as you pointed out, sometimes even the appearance of eye contact can be misleading.

I can personally vouch for the misleading aspect of "apparent eye contact" as I was hit by a motorist who appeared to stare right at me while he was stopped at a stop sign. He then pulled right out and into my path just as I was within inches of his vehicle and I had no time to evade his improper move. He was guilty of "Failing to Yield Right of Way" and was ticketed for it, and paid for his error. (I was injured and filed claim... this happened some 31 years ago.) Believe me, I still try to make eye contact, but I fully realize how false that platitude really is.

And how often as a cyclist have you seen the "Ghost Look" on a motorist... the Ghost Look is the look people give when they suddenly actually see you. This is the look on someone's face that has apparently been looking in your direction, and you think they are looking at you, but in fact they are looking through you, or past you... and suddenly you register in their mind, and they do the OMG thing as they now realize they were just about to pull right out into your path? Well certainly that is clear acknowledgement that you have made eye contact... but it is also acknowledgement that up until that moment, what appeared to be eye contact, was only the false "appearance of eye contact."