If you need a carwash, or a minor repair, or an oil change when in the area, Car Spa has more than one location and this one at the corner of Windy Hill and Hiway 41 in Marietta is perfect. They have deals on their website so you should print one of those to use if needed. Alot of times they offer a free carwash with oil change.
Best to travel the interstate highways. Most people drive autos extensively. However, you can get to Marietta from Hartsfield Airport using MARTA (Atlanta Public Trans.) and connecting with CCT (Cobb county transit).
CCT (Cobb County Transit) or car.
The Greyhound Bus Station is right on the corner of Hiway 41 (Cobb Parkway) and Hiway 120 in Marietta------
If you need to rent a car while in this area, Avis will serve you right and will pick you up and bring you to the office for the paperwork and to get your car.