I see your numbers but also see flaws in them.
1. 5 yr loan esp at 3.5 %, Try 36 months at 1.9-2.9% tops. That's easily another grand over your term.
2. Should have been able to negotiate 7-10% off MSRP
3. Those same $1500 cost of maintenance exist as I know of no leases that buy you tires , brakes not needed unless you drag them, etc.
4. That 5% you chopped off trade in was another $2500.
So using ballpark numbers and knowing 6yrs is definitely a long time and at this point its often is more about condition than mileage I see your $7000 number and have removed
~1000(finances for poor loan) + 1500 (maintenance-they all need it) + ~$2300 (for my 10% v your 5% negotation skills) = ~$ 4800+. So using your numbers I see you are still ~$2200 ahead.
Now the tables turn. My mileage is unlimited and hold true whether I drive 5000 or 50000 miles/yr. Obviously if its very low mileage, car is worth A LOT MORE at resale time which will further erode your savings. I can do whatever I want to the vehicle, say upgrade premium sound to superior sound, tune the motor, etc. You are stuck for 3 yrs with a potential lemon or vehicle that has a quirk you hate. I can unload trouble in a yr (take my lumps of course) or keep it forever if I love it and it is useful for my life. I am not easily impressed by the latest and greatest. I have a Range Rover Sport HSE for that BTW. Many states, I believe, consider a loan a liability on your credit rating, whereas a loan/purchase is an asset.
Now to really upset your numbers, do what I did. Haven't owned American (Isuzu Ascender is actually an Envoy gussied up) since my 99 SVT Cobra. Loved the powertrain but build quality was a Nasser POS. I voted for T so I put my money where my mouth was and revisited Americana car world. Was quite shocked at MKC quality, looks, and esp as a racer the way it drove thru the twisties on par with my X5's ! Was ready to buy a 2017 Reserve ~47000 (my deal would have been ~42000) when I saw a loaded 2015 MKC (identical car) on lot with 17500 on odometer. Why pay $42000 when I can walk out door for $29200+ tax ( btw much less due to trade in associated with the deal-> forgot to throw that into my pricing so take another grand off your deal) with a 3 yr note at 2.34% =$496.30/month. So except for the Ecoboost badge on mine v a 2017, 99.99% of the public thinks your car and mine are identical yet even with your numbers, I'm at or ahead of you, can do what I want to vehicle and as a bonus, will have an asset at trade in time which if I keep it for 5-7yrs may be only $5000, but if I drive it for 3yrs and put 50K on it, will be far closer to 10K in my pocket. while you are at ZERO.
I have always said it and stand by it, you lease if you have tax laws in your state (property tax that make ownership prohibitive-sketchy on this stuff), or its a business expense. Otherwise you lease it if you can't afford the extra upfront costs to achieve ownership that first time, which, in turn, allows you to climb the ladder with vehicles by always having a trade in to use as your downpayment. Even if you finance 50K everytime you get a new vehicle, every time you have a 10-20K trade in, you can buy that much more vehicle and have no negative effects on your ownership costs, or if you have reached that self-determined pinnacle, your ownership costs go down by 10-20K each vehicle.
I took 20yrs to climb that ladder, first with lesser known vehicles, then with some very savvy purchases during the recession. I see many young individuals foolishly thinking they are in same lap of luxury yet I own it, while they lease it. Go talk to any accountant and have them do the math. I did not get technical, I am not an accountant. My sis is a multi-million dollar financier however (has said no to Trump) and gave me my education VERY early in life. To this day, she won't buy unless its cash! God forbid you mention lease, and she just laughs having seen the extra millions the bank industry rakes in on leases v loans (reason they LOVE 60-72 month terms btw, yet leases still trump all that time))
Good debate. nothing personal. I just love to hold my titles and sell my unusual purchases on my own for lots of extra $$$.