They aren't going to sell your car. They will send it to auction. If you are not happy with the trade in offer you can reach out to them and have them go over it again. Maybe they did a trade-in price on a base Mustang. For 68k new I assume you got like a Mach 1. If you are serious about trading it, reach out to your sales advisor. Black book on a Mach 1 is closer to 60k CAD.
Sold my veloster private party for 2 grand LESS than what I bought it for 17 months ago and 12k miles later. Don't be lazy my friend sell your Mustang private party. Just watch put for scammers, but they subside after a couple of days.
Tesla trade in was the lowest offer I got when I was kicking tires.
Tesla offered me 27.5K for my 2016 Mustang GT Premium. I ended up going to all of the Ford dealerships in my area and all 3 offered me 29.5K for it. I sold it to the one closest to my house. Try the dealership.
This is one area I can’t stand about Tesla. I realize they don’t really want the used cars but when you can’t trade you lose the sales tax savings in a lot of states. It also complicates the process as you now have to shop your car at different dealers the week before you take delivery and compare the tax savings of a Tesla trade in vs selling the vehicle separately.