Being average is a good thing if you want to practice stealth wealth. Driving average cars allows you not to stand out.
Never Reveal Your Income
This is a rule that a lot of people talk about. If you were to reveal your income as something crazy high, people could see you as a target.
You may have a lot of money spread around in the stock market, real estate, and a personal business, but it is not all in one asset class that shows you are wealthy.
Diversify Your Assets
If you are flashy with your money, people will notice. If you practice frugality, those around you will not notice at all.