Sometimes the customer is right, sometimes the customer is wrong. I've seen both in the 20 years I've been making parts for the Mopar hobby. I've had several customers install their motor plates backwards and then they can't figure out why the engine doesn't fit. I had one very angry customer call me and cuss me out since the motor plate was offset. He told me that he had 40 years of Mopar experience and that the engine in a Mopar was supposed to be in the center of the car. He of course was wrong. Not sure if he was a stupid man or not, but the anger had made him stupid enough that he couldn't accept the truth.
Most aftermarket parts are designed to fit on an original car. Very few if any aftermarket parts are designed to fit with other aftermarket parts. As you add more and more aftermarket parts to a car the odds of stuff fitting and working gets lower and lower and eventually approaches zero. It isn't the mfg responsibility that the oil pump doesn't fit on your billet block which doesn't fit on the stock motor mounts and the headers don't fit on your raised port heads which don't work with your stock intake manifold. Ain't nobody responsible for that mess but the guy building the car.......
All very good points. I'll just add that just as the customer may not know when they're flat out wrong, the same could apply to you. I see no traces of humbleness or humility from the folks railing against "stupidity" here and that's a red flag to anyone.
Second, when people make a mistake (like thinking that a part should fit when in reality it's not compatible with their non-stock components), the seller's job to explain this to the customer in a way that protects the company's interest...meaning, you don't need to prove that the customer is an idiot to make your point.
Sometimes you have to lose to win. Give the fool their money back and figure out if you could have done something to prevent the mistake on the part of the customer. That might be cheaper than a prolonged fight with a customer who is surely gone forever, bad publicity and just bad vibes all around.
I hope it goes without saying that this is purely my opinion. I think a business can run however they want so long as they accept the consequences.
