2000 VR6 Keyless entry, Windows, and dome lights dead

I just bought a 2000 jetta glx vr6 3 days ago and now i am having electrical problems!
The day after i bought the car i noticed that when i turn the car off and take the key out of the ignition a loud noice starts coming from the speaker on by the side mirror in the corner of the window of the drivers door. Sometimes the sound does not stop either, it is going when i enter the car too. it even sometimes happens while driving the car with the radio on.

Everything else was working fine except for the memory of the drivers seat, and the cd changer in the trunk, until last night I was driving and suddenly i could not roll up any of the windows. i checked the window lock button and that was not the problem. both front and back would not roll up or down. then when i got out of the car i noticed that my keyless entry was also completely dead. no lock, unlock or trunk function. and none of the interior lights were working.

since my windows were stuck down, i tried and i was able to roll them up using the key in the doorlock. so i can roll them up and down but only from outside the car using the key.

i checked the fuses and they all seem to be fine.

does anyone have any ideas?

Btw, my gas door and trunk release buttons inside the car work fine, my power door locks work fine using the inside button. it also does have an aftermarket jvc bluetooth stereo in it which works fine.

thanks for any help

i also just noticed that the power mirrors and the alarm are not working as well.