No no no no.
DeLorean was not a coke junkie. He was arrested for agreeing to orchestrate a deal involving several million in coke... for the sole purpose of saving his company with the proceeds.
He was found not guilty as the FBI and DEA used an illegal entrapment... they brought the deal to him because they knew he was financially vulnerable.
The man was a brilliant. He was hired as an entry level engineer at GM. He moved up so fast in a company known for stagnation that he became the youngest person ever to lead a General Motors Division. Pontiac. The GTO and Firebird were his creations.
As for the car...He did use a lot of off the shelf components. I think they had a GM 350 motor and GM disc brakes all the way around. It wasn't so much that the car was a pos... it was a confluence of events that caused it to fail. Geopolitical issues in Northern Ireland where he located the factory, the U.S. economy, interest rates etc. That being said, the biggest reason was he was under-capitalized and ran out of money. In that regard he was no finance genius like Elon Musk is. But he was a brilliant brilliant car man.