2003 GMC Sonoma Owner's Manual - Page 124

Notice: Loading cargo that weighs more than 100 Ibs. (45 kg) on the luggage carrier may damage your vehicle. When you carry large things, never let them hang over therear or the sides of your vehicle. Load your cargo so that it rests on the slats and does not scratch or damage the vehicle. Put the cargo against the side rails and fasten it securely to the luggage carrier. Put the main weight as far forward as you can. Don't exceed the maximum vehicle capacity when loading your vehicle. For more information on vehicle capacity and loading see Loading Your Vehicle on page 4-49. To prevent damage or loss of cargo as you're driving, check now and then to make sure the luggage carrier and cargo are still securely fastened. Bed Rails If your vehicle has bed rails, they are there for appearance only. If you try to tie down a load with them, or to secure things in your truck, not only can it damage the bed rails, but the load can loosen. This could cause injury to you or others. Secure loads by using the cargo tie-down loops, inside the truck bedarea. 2-49