Just a wild uneducated guess, but just make sure your swaybar endlinks didn't come loose. Mine had one nut come loose and fall off who knows how long ago. It didn't make any noises but your car might have something similarly loose. Also check for any loose linkage or brake pads rattling in the rear brakes. Also, shock mounts. Check the bottom and top inside the truck for any loose bolts.
Check the trunk in the spare tire area. There's plenty of tools that can rattle over bumps, including the wheel itself and any jack/tools not tied down or snug in their positions.
And the mufflers, hangers, any corroded parts, etc. I hear muffler bearings can often lose their grease and start to rattle.