AC plug.

I noticed the AC plug in the car will keep charging/on if we leave the adapter in even after the car is off...does anyone face the same problem as I do? The battery will eventually run out if I leave the adapter in there, but it is a hassle to plug in and out whenever it needs to be used. Any solutions or suggestions I should do? Or there is a adapter out there to plug in but with the switch on and off, is there?

Yep. Same here. Just remember to unplug anything before exiting the vehicle.

I assume by "AC plug" you mean accessory plug as there is not an AC (alternating current) plug in the car - they are all DC (direct current) plugs. I've not had any problems with my phone charging cord plugged in with the car sitting for two days - the led on the plug draws almost nothing from the battery. Even leaving your phone plugged in wouldn't drain the battery since it will only charge when needed.

I have had many VW's and now Audi's The consistently on dc plug for your phone or other electronic devices does not drain the battery. The car is actually set up to always leave enough of a charge to start your car if you leave an item plugged in or a interior light on. Now if you leave the headlights on for more then 8 hrs you probably going to need a jump. You have to love the German engineering.

I've left my radar detector on overnight several times, and never had a problem the next morning with starting the car.

The always on feature comes in handy when you use an autovac...no need to turn the key switch!