I feel some of you are missing the point and I really don't know how.
I don't give a shit what kinda car it is. You don't want the business, send them away like a dumbass. Oh wait, that guy's an employee. This means shut the fuck up and do your job right.
"Well, they treated me good when I took my car there", is not an excuse for this shop. A KKK member may treat you good because your white, but that doesn't mean they're good people. In other words, if you want people to have respect and trust in your business, you treat everyone AND whatever they're driving equally.
"Well, they should've taken a Porsche elsewhere", is not an excuse for this a shop. I can understand where you're coming from, but their fucking job is to do the work and do it right showing the same respect they would for any other car sans personal reasons or preferences. Plus, it's not your fucking store, employee. You don't like your job, quit it.