I plan to build a pair of metal grilles for the bottom of the bumper, I want to know what are the exact measures
This your car? If so then Measure them.
Good advice. Scrounge a pair of stock grilles from Ebay or a junkie and fabricate from there. Never build anything from measurements that you didn't take yourself.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts
Related Models For Sale
Used Cars For Sale