I Think I could've saved a little more but I was still able to save roughly $18,000 in interest, fees, and protection plans/packages that I didn't want on a ~$30K Camry....
First I negotiated the out the door price. The sales guy wanted $30,950. I got him down to $29K OTD after I agreed to finance the car with him. (In hindsight, i probably couldve got him a little closer to $28K, but oh well).
Once in the finance office, I was shown a "menu" with monthly payments ranging from $621-$750 for different levels of protection plans. This is where they get most people. After letting him explain each individual protection package, I asked him what my base payment was if I decided I didn't want any of the plans. He reluctantly said $488/mo. I ended up declining all of the protection plans (extended warranties, gap insurance, dealer service plans, tire/wheel replacement, auto butler car wash, etc). He spent the next 15 minutes basically telling me I'm an idiot for doing this, lol. (Of course he did, they just lost the majority of their profit through the heavy markups on these items).
He gave me a pretty high interest rate of 8% too. Which, according to the YT vids I watched, they usually mark up several percent over what you would actually qualify for based on your credit score to make them more profit (they split the profit of the additional interest with the bank).
Luckily this didn't matter with the game plan I had. I agreed to the 8% interest and we made a deal.
What they dont know is, I'm going to pay the car loan off in full before my first payment (with some cash I had saved up and a 401k loan I just took out). This means I will not pay a single penny in interest to any bank. The interest on my 401k loan goes back into my 401k, so I'm just paying myself interest. That means I paid a total of $29K for this car, "almost" like I had purchased it with cash. (This is just the route I chose and I'm not recommending anyone borrow from their retirement account without weighing the pros/cons. In the long run, it is typically better to finance the car at a very low interest rate with a bank and leave the money in your 401K to earn you ~8-12%).
Had I paid his original asking price, kept the 8% loan with the dealer, and paid the protection package he was pushing the most (the 2nd cheapest one @ $650/mo), I would've ended up paying a total of $46,950 for the car.
Had I chose his top level protection plan ($750/mo), I would've paid $53,250 for the car. I could've bought a new Camry AND a Corolla for that price....
The moral of the story is, do your homework before you go. Shop around for the best interest rates on loans before you go and know exactly what rate you qualify for. Negotiate the OTD price as low as you can with the salesman (you really shouldn't pay more than the MSRP out the door). Agree to finance with them if that's what it takes to get the OTD price even lower (make sure they do NOT have a prepayment penalty. Almost none do and any loan over 60 months will not. My finance officer mentioned they did not have one without me having to ask which was nice). Then refinance with a bank of your choice to get a better interest rate a couple weeks after you get the car. Or tell the dealer about the good interest rate you got approved for and get them to lower their rate. If you want extended warranties or dealer service plans, ask the financial officer to break those plans down into total prices (not monthly prices) so you can see how much each plan adds to the total price of the car. Then you can decide if it's worth it to you. (They WILL negotiate the prices on these plans too, as they are heavily marked up. So if they have a plan you want, get them to show you the total cost of the plan, then talk them down.)
Hope this helps someone in the future...
These were a couple of my favorite vids. The second is basically the full experience, from salesman to the F&I office.