A post-dated check cannot be the basis of a bad check criminal case in Georgia.
I believe caselaw says so, in addition to the "present consideration" language of the Code itself. And, if you visit some of the websites of the Magistrate and State Courts around Georgia, many of them have "guidelines" that give examples of what could be, and what cannot be, considered "present consideration."
I looked up just a couple cases, and I think I was wrong about payments for the SALE of a vehicle. Only the first check, if given at the time of the original deal or pretty close to that time (days, not weeks) would be part of the deal itself, presently.
BUT FOR THE RENTAL of a vehicle, or renting a home or office space, or renting anything else, that's one of those special situations where the legislature has declared that they "are" present consideration. And a 1980 Georgia Supreme Court case says that there's a good reason for that-- since offering a bad check to keep something you've rented will have the effect of preventing or delaying the owner of the property in repossessing it. The Court found this law, and specifically the "rent payments = present consideration" aspect of it constitutional and not in violation of the "no imprisonment for debt" constitutional mandate.
(That's Cobb v. State, 246 Ga. 567 (1980).
More recent cases add that whether a deal is ongoing or has already been completed in the past may depend on many factors specific to that case, so there's no bright-line rule about the issue of when the goods or services are handed-over on one side vs. when and where the check is delivered. It's a totality of circumstances analysis (which means judges and juries have all the power to go whichever way they want it to go!)