Truck Forums - Whistling 2009 Chev Silverado

I recently had substantial body work completed on my 2009 Silverado LT. I observed a whistling sound afterwards that starts at 65 km/h to 90 km/h. It seems to disappear at 90 km/h.
I have taken it back to the body repair shop and they cannot seem to figure out the issue. I have tried so many things myself; taped bug shield, turned in mirrors, taped grill under wipers and nothing seems to work.
I would greatly appreciate any responses and any help. I have taken excellent care of my vehicle since I purchased it brand new.