There were several polls where people tried to find a correlation between the income and happiness.
The population of US as a whole indicated that increases up to 75K/year would make them happier, but further increase would not (average US family income is about 50-53K).
Anyone earning ridiculous amounts of money will make people jealous. Coping with that jealousy would make most people miserable and depressed. Imagine parking your lambo then returning and finding someone jealous has scratched the paint work.
It does not seem to happen around here (south of US) as there are lots of good cars around (mostly beemers and jags, though).
Not many lambos.