If they can get around the the alarm / no key / immobiliser situation then unfortunately I dont think this will make the slightest bit of difference to deterring them from your car... It probably adds another ten to twenty seconds onto the job maximum for the professional thief :x
I think you give them too much credit, the you tube videos show them plugging the kit in, press a couple of buttons hold the key against the unit and away they go :thumbsdown: