You can get voltage (12v ignition from the voltage rail underneath the steering wheel)
BeenverlichtingInbouwen_NDPHOTO_20121014_005 by ND-Photo.nl, on Flickr
12v geschakeld = ignition
BeenverlichtingInbouwen_NDPHOTO_20121014_005 by ND-Photo.nl, on Flickr
12v geschakeld = ignition