Check out these nice custom rear seat delete kits this guy is making himself way better price and quality. He has the letters cut out in the back seat area that say 4.6L or SVT or even Saleen or GT. He cut out the wood in the shapeof the letters or numbers and puts plexiglass behind the cut out letters or numbers, he even has pictures of the kit with a neon light in the trunk to light up the letters for at night, no it's not ricey at all, check it out.
http://www.cardomain.com/id/01lagunasecar
http://www.cardomain.com/id/01lagunasecar