Except maybe to you and a bunch of illegal Mexicans.
The "intent" is all that would matter.
merely applying green reflective material to the side of a crown vic, mimicking tha pattern on the side of a BP vehicle, would be effective enough.
3M brand ScotchLite
http://cms.3m.com/cms/US/en/2-135/cciurFQ/view.jhtml
Check you local plastics or sign supplies store.
I once sat at the counter in a hotel restaurant where all the workers were Mexicans. They were telling funny stories in Spanish, I undertood them and laughed. The two guys stared at me and then took off running out the back entrance. Thought I was INS, I guess. Adios muchachos!