I don't get it at all. You felt deceived but signed it anyway? So you knew about the 'demo' car before finalizing the deal, at the negotiated price? You don't think if you turned around they would have knocked off another $300? Let them sell a demo car at a new car price to someone else. - just tell them you'lI wait until a new one becomes available or search the internet for a dealer that has one coming in. I know, I know, you just wanted to get the deal done and felt you were already getting a good price.
This is again proves my point in the 'what did you pay thread'. People put in the effort to negotiate a deal, then when they get to the finance department they're to tired to argue - and the dealership talks about this at every morning meeting - they think that you want to buy a cay more than they want to sell one, but the truth is that they NEED to sell a car and you only WANT to buy one. IMO this is even worse than when you get to the finance department and they tell you about all the dealer add-ons that they weren't told about - pre installed VIN etching, paint shield, fabric guard, etc.
This is just my opinion, so please don't get all butt hurt about it. But there's an entire thread about 'what did you pay' with comments about questionable dealer tactics. .... A female friend of mine once asked me "why are men jerks?" I told her - "because there are women who will date them". So, why do dealers pull crap like this?.......