In the case of a purchase of a large ticket item, you can combine the sales tax from your car purchase with the standard sales tax deduction that is allowed from the IRS (therefore you would not need your receipts to take the sales tax deduction).

The sales tax from your car purchase is a deductible expense, but you must choose to deduct either your state income taxes from 2016 (any income tax amount paid from your 2015 state tax return and the state and local tax withheld in 2016) or the sales tax from the car plus a standard sales tax deduction allowed by the IRS.

The IRS has a sales tax deduction calculator that can be helpful in determining which deduction is the most beneficial.

IRS Sales Tax Deduction Calculator

Follow this path in the program to make the deduction:

1. Click on Federal Taxes TAB
2. Click on the Deductions and Credits SubTAB.
3. Choose the option "I'll choose what I work on".
4. Find the section labled "Estimates and Other Taxes Paid"
5. Click on Continue with Sales Tax.
6. Choose the EasyGuide option.
7. Enter the information about your resident state.
8. Enter the sales tax rate. You can find the rates here
9. Click yes to "Did you buy any major items?"
10. Enter the information about your car and continue.