Those of you who are convinced that you've figured out how this is supposed to work are ahead of me.
Let's say that on January 1 a man walks into his local Chevy dealer and asks "How much is that Chevy Bolt?" Does the dealer just knock $7500 off the price, then ask the federal government (the IRS?) to reimburse him? If some of the individuals who get the $7500 rebate/credit turn out not to be qualified for all or part of it, how is that enforced? Does the dealer have to report the transaction to the IRS? Does the IRS wait until it receives your 1040 for that year, match you up against their list of people who received the rebate/credit, determine whether you qualified for the full $7500, then add the difference between $7500 and the amount that you qualified for to your tax bill?