Doug....My Newmar, on a Freightliner chassis, has a hinge at the top and is screwed closed at the bottom on both sides. I suspect yours is similar. Since mine hinges at the top, I fabricated some hidden latches at the bottom corners so I could open the grill and easily clean out debris.
I used a thumb latch like those found on some engine covers and available at RV stores or online. Here are some photos: