I am interested in buying a used 2018--2019 Enclave that can tow 4000 pounds. I know from prior experience that fwd won't work so it will need to be awd. The Buick website says a towing package is available that will increase the towing capacity to 5000 pounds. It says the towing package is improved engine cooling equipment, nothing more. There is a long list of available extra cost "accessories" like a wiring harness, trailer hitch, trailer ball, etc. I want to know how to tell if a used Enclave has the towing package. I can buy and install all of those "accessories" myself if they are not already installed. I searched long and hard for a VIN decoder that would tell me but it was a waste of time. How can I tell if a used Enclave has the towing package (improved engine cooling)? I would also like to know what equipment is included in the towing package. Engine oil cooler, bigger radiator, more powerful radiator fan?