There are a few details still to be fine-tuned before Georgia’s new ad-valorem tax rules take effect. If all goes according to plan, though, the changes likely will eliminate the annual car tax for those who buy a vehicle after March 1.District 23 state Rep. Mark Hamilton said the annual ad valorem levy car owners must pay on or before their birthday is “the most despised tax that we have.”“Once we get this started, this will be a much easier, simpler and less expensive way to implement the tax,” Hamilton said.His fellow Republican colleague from Cumming, District 27 state Sen. Jack Murphy, said car owners soon will be “done with” the so-called birthday tax.“You don’t have to worry about it every year,” he said. “Plus it’s going to make it a lot less complicated when you’re talking about keeping up with all these birthday taxes being received at certain times of the year on certain birthdays.“Local governments are guaranteed by a formula that they’ll receive a certain amount of reimbursement to cover what they were receiving under the old birthday tax … [but] they lose a little bit of the guarantee every year.”Here’s how the new system will work: When a person goes to a dealership and buys a new or used vehicle, there will no longer be a state or local sales tax charge.