u must add the license plate to f bumper and rear bumper cfg
slot 0.000 0.035 -0.290 3.147 0.000 0.000 10 ; Registration
attach 0x???????? 1 ?-> ID frontbumper of that car wich u use
attach 0x???????? 1 ?-> ID rearbumper of that car wich u use
so u can attach the plate to each bumper u want
do only more attach files
and maybe correct the coordinates a bit so that it fits to the bumper u use
slot 0.000 0.035 -0.290 3.147 0.000 0.000 10 ; Registration
attach 0x0004D326 1
attach 0x0004D331 1
or copy and paste the 3 rows to ur f and r_bumper cfg
dont remember correct if its the f bumper ID and Rear bumper ID of all cars or if u hae to use the id of the bumper to wich it has to fit.. sorry ;-)