Do not buy the extras.
- Modern cars are well prepped against rust at the factory. Any aftermarket underbody or paint protection will destroy it.
- You don't need any Scotch Guard on the fabrics. That stuff is known to cause health issues. You really want to be sitting on that?
- LoJack is up to you. Most insurance companies will offer a discount on your premiums if you get it installed. However, the savings are sometimes negligible in comparison to the cost of the LoJack installation. So it might be best to call your insurance company and ask the exact discount you'll get. Then see if it's worth getting the $200+ LoJack. The main drawback to LoJack is that it's a passive system. So you need to know that your car is stolen so that you can report it to the police and have them scan for your LoJack signal. By then your car is probably chopped up and shipped to the border.
- Dealer prep fees are bullshit. See if you can get it removed or reduced. You're basically paying $200 for a car wash and for some minimum wage worker to peel off the protective plastic film from the inside.
- Extended warranties are not necessary on a new car. Besides, they often come with a lot of fine print and will only cover certain things.
Basically, they try to hit you will all this shit during the financing part. The easy way to handle this is during the sales/price negotiation part, tell them..
A) The exact price you want to pay on the truck out the door (including tax, title, license)
B) How much cash you're coughing up for a down payment
C) And the rest is how much you want to finance
Pretty simple math. So by the time you get to the finance guy, you'll easily spot any changes in the numbers if they try to sneak in some extras. And they will try.