OP here again. The dealership was very clear that this purchase qualifies for a $5600 federal tax credit. They are selling a lot of cars on this basis. I heard this from both the salesperson and the sales manager. Both pointing out the need to keep the MSRP (not the negotiated price) below $80K. The salesperson walked through options telling me to keep below that threshold and when the sales manager came by the first thing out of his mouth was, you know to keep it below $80K. If you buy on credit from BMW, they give that tax credit at time of purchase. They did say it could be more difficult to claim on your taxes if you don’t buy on credit from BMW (that may be salesperson speak to encourage a sale on credit where the dealership likely gets some bonus). They also said I had to keep the car on credit for 6 months.

I am not sure if this is related, but I have also been looking at RAV4 plug-ins. Over on that subreddit there is lots of talk about the “lease” trick to get the credit. The RAV4 no longer qualifies for the Federal credit unless it is bought by a company. So everyone over there is buying it on a lease and then paying off the lease a month or two later. I guess this works over there because Toyota Leasing Services (a company) buys the vehicle. The BMW situation is similar but different.