DynoDan, I found a vent cover here:
22 inch square is a standard size, and most fit all brands, as long as the size is correct. May try this. or at least bargain on price with your dealer. Also, I didn't shop long, nor have I ever done business with this company, I just happen to have checked a few things on their site, and their prices seem reasonable, but as always, BUYER BEWARE.
2012 Ford F250 ext. Cab 4x4
2002 Jeep Wrangler Sahara
2008 Yamaha V-Star 650 Classic
2008 Work and Play 18LT