Tips on Buying Cars: purchased a used car, windshield, paper work

Question
I purchased a used car from a dealer that had the price of the car on the windshield. We negotiated a trade in from that price. When i got home I looked on the internet and found that that same car was listed on there 500 dollars cheaper then what was on the sticker at the dealer. I have not yet paid for the car but signed all the paper work for it. But when I go to pay for the vehicle today I want them to take the 500 dollars off. Do I have a chance?

Answer
With a trade involved, this gets complicated; they can say that they added $500 in value to your trade-in, etc...  I'd print out a copy of the online ad, take it with you and tell them you feel that this is the price they advertised, and that it should be the selling price.  I'd also make it clear that the value of your trade-in should have nothing to do with the selling price of the car you're buying, that your trade-in is worth what it's worth.  Hey, what do you have to lose?