You'll always get a better discount on a car sitting on a dealers lot. The longer it's been sitting the better. A 10% discount is certainly not out of line for a '17 model year. The changes from '17 to '18 are minimal (if any??) so you won't be missing much with the '17 model. In the NE USA a winter buyer is in a good position when purchasing a car on the dealers lot - especially if they have to clear the snow off it! However, keep in mind that the longer you wait the remaining inventory will shrink leaving you a lower chance of getting a car with the options you want.