The horse is dead

I would if I knew that guy would appreciate my patience and go tell all his car buddies that I'm a pleasure to work with, then I'd get more business and a good reputation. Sometimes doing favors for free in the short term gets you more money in the long term, among other good things. I've seen plenty of testimonials on here proving that.

Work for free???

He bought parts from him, that's not free, Dave made money off the sale... When you sell products and people need help/advice, that goes with the business - it's called support...

Refund most of his money??? $200 restocking fee is pretty steep... $20 restock fee is more reasonable, especially when the customer is paying the return shipping...