I just happen to be going through this right now. Great thread. I had to cut almost all the bolts to get the grill trim off.
I called Mr. G's today to order the FA 2573 trim clips/studs that Redfish used. However, the guy at Mr. G's said that they are no longer available, and he suggested the FA 4411. It is a little more "rounded" at the back, and would take more grinding to flatten, so I decided I would just go with the bolts/speed clips method since I would have to grind the bolt heads anyway.
Anyway, I'm glad I found this thread, I was wondering how I was going to mount my grill trim.