A photocopied Tag! That's very unique and a GREAT idea! Unfortunately, here in Florida, beginning June 1, 2008, there is a new Law that allows LEO to confiscate your tag if it is covered, has any modification such as a PBA sticker or Sheriff's badge or any addition to it and leave you on the side of the road. It's a great thought though!
As to the install, as close on the vertical and horizontal axis to the headlights as possible up front and as for the rear, well, with your paper plate (

) you would want to be as close to the taillights as possible but with an LI Slim sensor set-up mounted using the supplied, slim sensor aluminum mounting brackets attached to the license plate area will do just fine.!
Cliff - C55