I just bought a 1999 Oldsmobile Silhouette that has a hitch on it. Is there a way to tell if I have the factory towing package or if this is just an after market hitch that''s been added? I''m thinking about buying a pop-up camper, but I need to know what my weight limits are. If it''s the factory towing package, I know it pushes the total towing capacity from 2000 lbs up to 3500 lbs.