i don't know about a kill switch, but in my e30 if i take out the empty button out of the dash, it kills the power windows completely
'Arrest Me Red'
mods to come:
New Badges - Check!
Muffler - Check! - Ansa free flow
Sport Shocks - Bilstein
Keyless Entry + Alarm - BMW Security Systems
Power Flow Intake
THE founding member of "i don't hate on del"