I have a Toad alarm and immobiliser on a Saab Classic convertible and it is way better than the factory fitted alarm on my 2002 Defender. I had it professionally installed 10 years ago and haven`t had any trouble at all with it, whereas the Defender alarm remote control is fairly temperamental, as is the central locking. I would definitely have a good look at another Toad alarm if I was replacing the alarm on my Defender.