I just found my Perma-Plate warranty contract, here's what it states:
LIMITATIONS OF COVERAGE
This warranty does not cover damage existing prior to the application of the Perma-Plate products, or to surfaces not treatable with the Perma-Plate products such as semi-gloss or non-golssy paint, headliners, seat belts, steering wheels, or as determined by the design of the vehicle; damage caused by road hazards, vandalism, collision or similar accident; fire or other natural casualties; rusting of metal; modifications or alterations of the factory's original painted finish (i.e. repainted surfaces, aftermarket pin striping, etc.); defective paint (i.e. peeling or chipping of paint or factory clear coat, paint separating, cracking or flaking, or as determined by independent inspection or factory bulletins); chips or scratches caused by every day use or other causes or damage caused by neglect or abuse; stains or damage caused by dye, ink, tar, gum or paint; bleach, acid or other caustic or corrosive substances; burns, rips, tears, shredding or other interior fabric or leather damage resulting from vandalism or other causes; abnormal use or damage due to neglect or abuse; surface wear or natural creases in leather seats; modification or alteration of leather or vinyl surfaces; damage caused by rusting or poor adhesion to the surface to which the leather or vinyl has been attached or manufacturer's defects.
I'm guessing the abuse or neglect would apply to the left on bird sap/bird bombs.