A4 1.8T, USP, 2004. I did many searches and even when I found others with these issues, they seemed to go unresolved. At this point, I am only trying to fix to sell the car -- worried about this slippery slope. I am not convinced all these issues are related either. I have a Masters in electrical engineering, so I attempted to look at this from all aspects and angles, but nothing makes complete sense. I checked all the fuses, and these issues run across many fused circuits. I discharged any parasitic capacitances (disconnect battery and short cables together) as another thread stated this could maybe do the trick (reset registers forcing a re-read of memory for correct configuration data, etc.

ISSUES:
1- Radio started out as staying ON when I turned the car off. Previously it would turn OFF with the car (months ago) turning off.
1a - Radio started to turn off automatically if turned on by someone. If off, then it would not automatically turn on. However, if it automatically turned off(after someone turned it on) it would come back on automatically. This has drained my battery since sometimes it may automatically turn back on after car is off and at first we did not know what was going on.
2 - Sunroof was possessed for a while but worked. Then after one of my battery drain issues, it stopped working completely.
3 - All power windows stopped working and same with trunk release. This is on the remote or the button on the car (button on front door or on trunk). None of the windows will function at all. These worked fine while the radio issue was going on initially. My wife went to east coast for two weeks, car was dead (assumed it was the radio draining it due to some type of radio drain issue), after I recharged the battery, the windows and trunk did not work as well as the sunroof.

The remote works fine otherwise, and all the door functions work fine too. Even the window lock-out still lights up when pressed. The mirror control works fine, etc. I did notice there is excessive drain on battery when turned off -- 250mA up to 750mA, but again not sure if this is all related. That could just be related to one of the many faulty circuits. ...common for people to get confused trying to find a single fault for a multi-fault problem.

The car does have an aftermarket Viper remote start and its had this since 2004. We have stopped using it 6years ago because we broke that remote -- have not had a problem that we know of with that device (would not know if this was causing something though).

Any help is greatly appreciated!