98 A6 Alarm help?!
 

ok so the alarm horn went out, and sounds horrible, i ordered a new siren and its got the shock sensor. now i have 2 questions really. one in order for it to work i need a hood pin switch, does the car have one, do i install one, or wire it to something else? and two where is the alarm brain located, or is that in the siren that died and i removed that was located next to the cd changer in the trunk? please help!

thanks pletsch