Generally speaking, the best time to buy a new car and get advantage of as any discounts as possible is toward the end of the year. For example, I bought my car at the end of the year, just before Christmas. I did not purchase the most recent “version” of the car. This was at the end of 2015, and dealerships were trying to get the “old” 2015 stock off the lot, so I saved a ton of money by getting a 2015 instead of a 2016. It also opened me up to getting 0% APR financing, since they just wanted to sell the car and get it off the lot before year end.
Keep in mind, I work for a US OEM, so I cannot guarantee that any of the “foreign” automakers do the same, but I would honestly be surprised if they didn’t.
Another thing I forgot to mention is that there are often “loyalty” discounts… let’s say you’re leasing a Jeep. You might be able to get or negotiate a loyalty discount by buying a Jeep (or some other vehicle from FCA). Similarly, sometimes you can negotiate an early trade in for a lease if you’re getting too close to going over your miles, but there are sometimes timing restrictions on this sort of thing.
Go in knowing more or less exactly what you want, and be sure to tell them that. If they try to push you into something else, just say “No thank you, I have done my research, this is what I want.” If they don’t listen, leave. There are thousands of dealerships and salespeople who will respect what you want, simply because they want you to refer them to others.
Let me know if you need any more information! One other tip: shop around. Just because one dealer won’t give you a deal, doesn’t mean another won’t. Each dealership is individually owned, and not controlled by the OEM, so it is solely up to the dealership whether or not they give you deals/discounts!
Finally, don’t let them put that license plate frame on the back without forcing them to give you another discount for advertising for them! Sure, you can always take it off later, but use any and every tool you can to negotiate as much of a discount as you can! (Don’t use this until you are ready to sign though! You don’t want it to mess with the rest of the deals you are likely getting.)