After working at a Jeep dealership for a while I have learned that you do get some wild card cars every now and then that just have some strange options. Right now we have 2014 Grand Cherokee Laredo base model but it has a power rear lift gate, sunroof, 4x4, 8.4" touch screen but no back up camera or leather interior or backup sensors. Customers will also want certain add-ons but not entire packages. The guy who originally bought your Jeep may have said "ok I'll take the Jeep if you throw in a gas tank skid plate because I think it is vulnerable and I want an auxiliary transmission oil cooler to make sure the fluid stays cool" and the dealership did it to make the sale.