Whilst tidying the dash install after an alarm was fitted, I found the wires for that annoying "key in" alarm.
It is a two wire connector in a T shape. The wires are black and black with a white stripe. You will find them about halfway down the steering column.
I have not found any adverse effect as yet.
It's great to be able to leave the radio on and door open without that buzzer going off.
Yours
Nigel