Western Europe has generally higher social mobility by most metrics than the US (mobility between income cohorts, education level vs parents, etc). The US probably does have more people becoming really, _really_ rich, though, and also has slightly different social norms around money and the showing-off thereof.

(That said, this is mostly differences at the margins. The mean price of a new car isn't much different between the US and the wealthier EU countries, say; the upper-middle-class are happy enough to buy cars that cost more than an average annual household income in both places. It's where you start getting past low six figures that people start getting squeamish)