My $.02 worth. My last 2 car purchases were 1 year old cars with about 7-10k miles on them. I got each for over $7,000.00 off their sticker BEFORE even seeing them using the fax method described below. I heard about it from a BMW dealer and it has worked for me twice!
1) Know EXACTLY want you want before sitting down with a dealer. Learn EVERYTHING you can about the make and model you are interested in. Different motors and transmissions, body styles, sport packages, available options, interior styles colors etc etc etc. RESEARCH how much $$ cars with similar options are going for.
use this as a GUIDE.
2) Draft up a list of your likes / dislikes from #1 above and fax (yes, seems oldschool) your list to local dealers with what you are looking for. Only give your last name (Mr. VooDoo) Ask in the fax for them to return their availability to you by fax. I did this at age 17 when the dealers teated me like crap in person and tried to sell me junk yard look a likes for thousands more than their value.
3) Above all else, go to the lot KNOWING you can always come back another day, week, month and get something VERY comparable. Keep telling yourself YOU DO NOT NEED TO BUY ANYTHING TODAY!
Best of luck, and report back how you do.