You can go with the dealer, but USAA offered me a warranty on repairs / quality of workmanship back in the U.S. if Brixner performed the repair.
If Neiderlassung does the repair (and I doubt they have an in house paint booth) and 4 months after arrival in the states the front spoiler starts to fall off or the paint bubbles you will have no recourse. The odds of Neiderlassung screwing this up are to none. So it's something to consider.
The governement will only reimburse you up to your deductible. If you were going to the Gym as part of your physical fitness regimen it's part of your assigned duties or "in the line of duty" so make sure you place that in your statement. It will strengthen your position/case.
Also, take another picture if the grill with a size reference like a ruler or something.