To follow up, here is the lemon law information about depreciation calculations for MD and PA:
MD: "If your car is a lemon, you are entitled to a replacement vehicle or the manufacturer must refund the full purchase price minus an allowance for use, not to exceed 15 percent of the purchase price". So if you paid $40,000 for example, the most they could deduct would be $6000, which is less than the Federal tax credit, which in my opinion is a pretty big win. But I'm making a lot of assumptions here of course.
PA: "The manufacturer is allowed to receive a reasonable offset for your use of the vehicle that you are having problems with. That refund offset can total no more than 10% of the purchase price of the vehicle or $.10 for each mile driven before the first reported repair." Just note that the PA lemon law only covers the first year of ownership so technically we're not eligible under the Lemon law, I don't believe. That probably doesn't matter as it appears Hyundai is buying the cars back either way and just using each state's law as a guide for how to determine depreciation. If that's the case then I'm likely going to be very happy with their offer, since I live in PA. If the max they deduct is about $4000, I would of course absolutely take that.
Anyway, as I mentioned once already, I'm making a lot of assumptions here. Either way at least folks in these states at least have some idea what the law says, might come in handy when in discussions / negotiations about the buyback.