Most of the people here have ordered at 8-11% off MSRP + the $7500 rebate; which is how they have gotten the payments so low.
To me it looks like you paid ~$6,700 over MSRP. I calculated this by using your gross cap cost, minus MSRP, minus fees.
So most people are saying you overpaid by $13,000 which is the $6700 plus the $6500 you didn’t get discounted.
Had you used a broker you could have received a lower monthly payment and kept the $13500 in equity.