Look here;
http://challenger.mpoli.fi/forum/viewto ... =4119#4119
If all the numbers shown here on the body, engine and transmission match then the car is "numbers matching".
Broadcast sheets can be found;
Taped to the back side or top of the glove box insert
Under either or both front bucket seats tucked in the springs
Inside the removable plastic bucket seat back covers
Under the rear seat bottom
In the rear seat back
Under the rear speaker shelf
Under the carpet.