Car powers off randomly

Electrical problem 4 cyl Front Wheel Drive Automatic 57,000 miles

Hello, I've had a vw jetta 1.8t for about a year and basically what will happen, is, randomly the car will completely shut off, tachometer is idling correctly. It normally shuts off when coming to a complete stop, but has done it while driving at about 40mph, (when shuts off while driving, it does not completely shut off, it kinda resets the power in a way, all lights everything turns off and then powers back on and car run normal)

After the car completely shuts off, it may start right back up, it may take a few minutes, but then starts up no problems, (during this time when I turn the key and it doesn' start, nothing happens, does not try to turn over, no sound, nothing, even emergency flashers won't come on).

In addition to this strange loss of power, tripometer and clock reset. It does this more often with the ac on, but has done it also when the ac was off. It has done this when the engine is cold or hot, Overall, my interior, dash and outside lights flicker practically all the time. I have a feeling this issue is connected somehow.

Now for what i've done to try and fix this, first off ive taken it to the dealer, spent 400$ and they remvoed an aftermarket alarm that was already in it and the lo-track gps they put on their sold cars and rewired everything,
About a week later, it started doing the same thing. I figured it may have been an issue with the lock on my door, since I lock and relock my door a lot. So I took it back to the dealer, they could not duplicate my issue.
They tested everything on it, fuse box, alternator, battery, everything. They said they may need to keep a few days, but felt they're was nothing wrong, or had anything to do with what they fixed. I thru out my theory about the door lock and they said don't lock it and see what happens.
Well, for about 3 months nothing did, car ran fine, never powered off, even lights stopped flickering, But the gremlins came back, same issue, keep in my mind I have not been locking it.
I will be taking to dealer soon, but thought I would ask anyone, if they had any ideas, battery and alternator were checked recently so they are good, any help would be appreciated

p.S. Sorry for the wall of text, issue is too complex to make long story short.