Please, please, please, please don’t do this.
$700 a month for a leftover Ford EV is DoA.
(They’re still leaving 2023s?)
How many other offers have you gotten for the trade? Pull that out and deal with it separately.
Also, double check all of your inputs.
Incentives are taxed in CA so for sure you aren’t accounting for close to (or depending on your location, more than) $1k in sales tax.
(I didn’t look beyond that.)