How did Danny become so successful? Owning the top Luxury Car Dealership chain in the valley?

It obviously could be possible, but we never learn how he went from a teenage Karate champion to successful business owner of multiple luxury car dealerships. Usually the people who achieve this level of success are multi-millionaire entrepreneurs who own other large companies and businesses as well. Or of course super star athletes of the NFL, Golf, NBA, etc.

Karate, especially a teenage karate champion of a local Valley tournament would not have that kind of wealth or endorsements or even fame.

Also on a side note. Have any of you ever worked in a car dealership before? I have and it was a completely different experience from Larusso Motors. The sales managers, and GM at the dealership I worked at were total creep a-holes, on coke and treated everyone like garbage and used intimidation tactics to try to scare all the employees to sell and stay in line.

I'm not sure if any dealership is like Daniel's where you are actually treated that well and it not being a hostile environment?