Not really a horror story but when I bought my 370Z the dealer screwed up the paperwork and UNDERCHARGED me by ~$1,500. They had actually added the amount I owed on my 07 to the down payment rather than adding it to the price.
They called the day after delivery to explain their mistake and to ask me to come pay the rest. I found it pretty comical that the FI guy made the Salesman call and attempt to explain before he just transferred me. I'm sure that if the tables were turned I would have had to fight tooth and nail to get a refund and I'm not sure of what sort-of liability I actually had considering the contract was signed by both parties, but I went back the next day and wrote them another check...
I shortly considered not going back to fix their mistake because of how I was treated when I bought my first Z from them but I just couldn't do it.
