Depends on your definition of wealth. The definition of wealth that I follow is not how much YOU MAKE but how much YOU KEEP. If I'm keeping $500 at the end of each month, I'm wealthier than people who have NOTHING (like my poor brother) at the end of each month.
As for having a decent car, I would never pay $18,000 (36 months X $500) for a brand new car. Whenever I had a car, I paid $1,600 in CASH for a 15-year-old car, and budgeted $400 for liability insurance, $1,500 for fuel and $1,000 for repairs PER YEAR. Collision and liability insurance for a brand new car would exceed the annual cost of an old car. I'm taking the express bus to work for $140 per month, as I don't have an urgent need for a car.
I didn't mentioned in my comment about how much money I'm putting away into my retirement accounts. The final figure will be much larger than $150,000 plus interest in 25 years. The $500 per month is what I stashed into savings.
If you want to learn about true wealth, read The Millionaire Next Door. It's isn't about having a brand new car.