I usually get a certified used between 25k-30k miles, older year the better, preferably 3-5yr old. That alone knocks an easy $8k off the msrp for a relatively newish vehicle. In addition, car lots are eager to ditch these older cars in favor of the newer year cars coming in, so lots of room to haggle. And don't forget, the dealership will always ask you how much you want to pay per month, always. Don't go that route; they will skew the numbers to meet your goals in their favor and you may end up paying a higher apr for longer. Remember, there are three separate deals to be made, all independent contracts; how much they will accept your trade in for, how much they will settle for the car, and from their banker, what apr they will give you. On that last one, I always go into my credit union and get pre approved for the lowest apr before going to the dealer so we can skip the whole run-around and talk business. Just my 2-cents.
"The true value of a human being is determined primarily by the measure and the sense in which he has attained liberation from the self." -Albert Einsetin