Is it possible to buy a new Volt and have the dealer take off the $7500 tax incentive? I don't have enough tax deductions to take advantage of the incentive but I hate to leave it on the table. My only other option is to buy used where the tax incentive has already been used. Appreciate any and all feedback.
"Tax deductions"? You must mean not enough tax liability. Adding more tax deductions causes your tax to go down, not up. Let's double check what you mean. Take a look at your 2016 1040 line 44. If that amount is greater than $7500 and you will make about the same income in 2017, then you should be good.
if it is below $7500, then you could (1) go earn more money - more is never bad (2) do a Roth conversion to generate that liability (3) if you are at retirement age, withdraw more to generate a larger tax liability (4) sell some investments to generate some capital gains tax (5) reduce any charitable giving to reduce your deductions (6) a number of other things I haven't though of that others may suggest.
As for trying to get the dealer to take the tax incentive - don't do that. It's called tax fraud. People go to jail for that.
The last option is to lease the Volt, the leasing company then takes the tax credit, and it's up to them how much to apply towards your purchase. Usually you don't get the first $7500 and I think leasing is the worst possible way to own a vehicle (others on this site will disagree with me, but most of them aren't in the double comma club either).
The amount you can get has nothing to do with your tax refund (maybe that's what you meant by deductions). The year I bought my volt, the IRS cut me a $10K check as I had a refund coming and the tax credit bolstered that refund by $7500.
Remember, the goal is to pay more tax not less... if I had to pay $1M in taxes, that means I'm making a whole lot more.