Yes I had the same comparison having also rented several VWs in Europe and feeling like it's an entirely different car in the US.
Not sure whether a US market BMW is produced locally. If they are that would explain a lot in terms of US customers complaining about reliability and thinking a model 3 is like a German luxury car while to European customers it feels like a cheap American car. The frame of reference isn't the same.
Edit: So a quick Google shows a US BMW 3 series is produced in Mexico. And apparently has to use at least 50% locally made parts according to Mexican law.
And just so I don't sound like a Tesla fanboy or anything, I got a Model S high mileage loaner that also felt like it was about to break apart at any second.
I guess Americans just can't make cars! I hear the Chinese made Model 3's are really solid