Audi Repair: 2001 Audi A4 2.8, hood latch, electrical functions

Question
My car alarm started going off for no reason.  Took it to audi dealer, they said hood latch and sensor was defective.  I took the car to my local mechanic who cleaned the contacts on the hood latch and the problem went away for a month.  The alarm started going off again.  I took the car to the same local mechanic who removed the entire alarm system.  Everything worked fine for about a month then my battery went dead.  I took the car to same local mechanic an they replaced the battery (which was only 2yrs old).  A week later I noticed that the lights were going off as if the alarm had been triggered (minus the horn).  I took the car to the mechanic and told them that the alarm appears to be active still and that I probably didn't need the new battery in the first place.  I went by the shop to pickup the car yesterday and the stereo was unable to produce any sound it appeared to be working though.  Question: how can I completely disable the alarm system without losing other electrical functions?  I don't drive much, I just want the car to be reliable, other than these electrical issues the car has been very reliable.  Should I just trade it in?  Thank you so much.

Answer
It sounds like the dealership never actually found the problem, but started guessing.  Normally they start guyessing and throwing expensive parts at the problem; sometimes they even hit the right part, mostly they don't at the first try.  The alarm starts to go off when there is a current drain, on mine (2001 S4) the dealer could not find anything either, it turned out the Nav unit had gotten wet and had corroded to the point where it was shorting out.  I would check the current drain on the battery, there should be no more than 50 milliAmps of current flowing when everything is off and the doors are shut.  I would start there.

Let me know what you find,  Jan