Well, this is certainly a weird one for me. We just got a 69 GTX convertible and although the fender tag is not coded for factory under coating, the under carriage of the car is under coated like the factory would have done. Where the seat mounting stud areas are there is a clear area where the 1" masking tape covering the holes were. It also appears that the undercoating was applied from the middle of the car being shot outwards to the outside of the car due to the coverage pattern. Could the factory have put undercoating on a car and not had it coded on the fender tag? The under carriage of this car is totally untouched or unrestored and we are taking many, many pics of all the inspection marks that we have come across when we are degreasing it all.