I struggle with this as well.

I have an '09 4 door 4x4 shortbed CTD.

It runs like a swiss watch and drives perfectly but the body is starting to show signs of age.

Not having a payment is awesome and I've pretty much decided to keep it and started daily driving a beater Buick I bought in the neighborhood.

'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.