Derby Parts › Crown Vic Hump Plates Crown Vic Hump Plates from $60.00 24” Crown Vic hump plates with holes for plug welds. Available in 1/4” and 3/8”. Sold as a pair. Thickness: Select Thickness 1/4" 3/8" Add To Cart Added! 24” Crown Vic hump plates with holes for plug welds. Available in 1/4” and 3/8”. Sold as a pair.