I did some digging around for you, and I thought this was illegal in MA, since I have backed out 2 deals before, and got my deposits back both times, anyway, here is some info:
Deposits In Dealer Sales
You may be asked to leave a deposit to hold a car, even before you have agreed on all the details or your financing has been approved.
You should be aware that the dealer may not be required to return your deposit if you decide to cancel the deal and if:
You and the dealer have signed the contract and;
The contract has a special section on the front page, clearly blocked-off, that states the circumstances under which your deposit will be kept and;
The specific dollar amount is filled in and;
You initial that clause, separately from your signature at the bottom of the contract.
Do not place a deposit on a car unless and until you are serious about buying the car.
this info is from
http://www.massconsumers.org/carsmart/003-5.html
more info from mass attorney general:
I am negotiating the purchase of a car with a local dealership and they are now asking me to place a deposit to "reserve" the car I want. This should be refundable, right?
A: That depends. A dealer may not be required to return the deposit if you and the dealer have signed a contract that specifies what is to be done with the deposit. Do not place a deposit on a car unless and until you are serious about buying the car, and try to make your deposit as small as the dealer will accept in case you have to forfeit it. It is important to remember that there is no automatic cooling off period, or three-day right to cancel an automobile contract in Massachusetts. Your deposit may depend on other factors in your agreement with the dealership, so be aware of the details of your transaction. Buying a vehicle is serious business, so do your research and read any contracts carefully.
hope you didnt sign that section that you are willing to give up the deposit, etc. I swear, I thought we have the 3 day cooling off period in MA, oh well...