This thread hits my #1 "pet peeve" since purchasing my coach (used). We didn't even realize that the front A/C cover was missing which kept it from blowing cold air. I paid a local dealer to replace (& paint) a new cover which ended up flying off on my very first trip. I got the dealer to replace it under warrantee to only have it come loose on my next trip to North Carolina.
My son & I discovered the same issues with the mounting method but more importantly noticed that the cover is actually larger than the unit's mounting. We added 1/2" weather stripping competely around the mounting surface to take up the space & help seal it. We relaced the screws with #10 sheet metal type screws, flat washers, & locker washers.
We also drilled new holes along the side and added additional mounting screws & washers. You may not like the idea that these new screws are easily visible from the ground but I prefer "reliability over appearance". It's not that big of a deal to me.
Since having so many problems with these covers, I now use a 2' bungy cord across the middle of both covers. Again, I prefer reliability over appearance and find it EXTREMELY annoying when a cover comes loose while traveling. Eventually, I hope to trust the mountings enough to eliminate the bungy cords.
I emailed Dometic Technical Support about the fact that these covers do not seem to fit more correctly on the Penquin A/C units. They replied with how great their products are and apologized for the problems I'm having. NO REAL SOLUTION OFFERRED! They're obviously in denial!?
Bob Bowers (Surprise, AZ)
2003 Alpine Coach 40' FDTS
2014 Jeep Cherokee Lattitude