This is the last one I'll post, but, there is a very important lesson in this one. If you go through the dealer for the financing, wait a few weeks and then call the bank and request copies of the loan documents the dealer sent to the bank. Compare this with the copy you received when you left the dealer and see if any of the amounts have been altered and your signature was forged.
Unscrupulous finance managers will forge documents after you signed the contract to benefit themselves and/or the dealership. This could range from lowering the interest rate and charging you more for the car so the dealer pockets more money, or lowering the rate and signing you up for a highly marked up service contract which puts more $$$ in their pockets. They may even change the service plan you voluntarily purchased to a lesser plan or cancel your gap insurance to put more money in their pocket.
If this happens to you, it is outright fraud. Contact a lawyer. Consumer protection laws in Maryland require the dealer to pay your legal fees if you win. I believe you have 3 years to sue, so pull out your old contract now and go over it. They'll stop doing it if enough people wake up and sue their pants off.