How do l generate a 7500 fed tax liability to receive the full 7500 E.V. tax credit? I'm on fed. salary and normally have a tax liability of around $3000?

I have submitted such credits, I recommend inquiring about carrying over your rebate from the previous year, like carrying over donations not claimed.  You qualify for what you have paid this year and next you requalify with the carry-over of the difference. Policies are modified often when contemporary issues emerge.  If the IRS has a policy, you will find it within the code. If it is not found your case may change the policy or clarify the policy. I was audited three times over new species of insect donations to museums.  For years, people have donated to museums, and many have received tax deductions.  Suddenly there were new folks on the block in 1988-1989 who disagreed about the current policy. It became codified to the advantage of the collector. It was a reasonable change since the basis of the insects could not be assessed. The value of a new species had an unknown value. The cost of obtaining could be used to establish a value of each insect donated.