The only hitch available for the 2022 Audi Q3 S-Line is the Stealth Hitches Hidden Trailer Hitch Receiver w/ Towing Kit item # 391AUDQ319T. It installs behind your rear bumper not beneath your vehicle. This hitch is custom fit and has both a removable 2" receiver for accessories and a removable ball mount for towing.
The best part about the Stealth Hitches item # 391AUDQ319T is that when you are not towing a trailer or hauling an accessory your Audi will look like it came from the factory.... view full answer...
The battery type doesn't matter in this situation as you could still face this issue with two AGM batteries. If you're vehicle is running the alternator should be charging the start battery more than the draw from the 7-way 12v accessory pin. As long as the alternator is properly functioning you shouldn't have an issue charging both batteries while driving.
If the vehicle is off and the 7-way isn't tied to the ignition for power then you run the risk of draining the start battery if you're... view full answer...