What version of turbotax do I need if I bought a car in 2018 and want to deduct the sales tax?

Deluxe will work.

You can enter the sales tax you paid for the car you purchased in 2018 by going to Federal>Deductions and Credits>Estimates and Other Taxes Paid> Sales Tax.  You will be asked if you paid sales tax on a major purchase, and you will be able to enter the sales tax you paid for your new vehicle. 

Sales tax is an itemized deduction.  If your state has a state income tax, you have to choose between using the deduction for your state tax paid OR the sales tax deduction, whichever is higher.  The TT process will suggest one or the other as you prepare your return.

“Major purchases” that you can enter for the sales tax deduction include:

Motor Vehicles (cars, trucks, motor homes, RV’s, sport utility vehicles and off-road vehicles

Aircraft or boats

Mobile homes

Manufactured housing

Building materials for major home improvements

You cannot deduct: furniture, jewelry, home electronics such as TV’s or computers

https://ttlc.intuit.com/questions/1901222-which-deduction-should-i-choose-sales-tax-or-income-tax

https://ttlc.intuit.com/questions/2566624-how-much-sales-tax-did-i-pay-last-year

https://ttlc.intuit.com/questions/3148443-how-do-you-define-major-purchase-or-major-item-for-the-sales-tax-deduction

https://ttlc.intuit.com/questions/1900791-how-do-i-find-my-local-sales-tax

https://ttlc.intuit.com/questions/2566624-how-much-sales-tax-did-i-pay-last-year