DUCK TAIL SPOILER 72 CHALLENGER

HELLO FOLKS
I BOUGHT A "TOP OF THE LINE ORIGINAL REP." DUCK TAIL SPOILER FOR MY 72 CHALLENEGER, IT HAS A SLIGHT BOW/RADI/CURVATURE IT DOES NOT FOLLOW THW STRAIGHT LINE OF THE TRUNK LID
IS THIS NORMAL WITH THIS SPOILER I HAVE SEEN A LOT OF PICS WITH THIS ISSUE
THANK'S FOR THE HELP