Holding in the CLUTCH holds the current auto gear preventing the truck from upshifting while throttle is being applied.  


This feels like something that would be fairly easy to implement and give the driver more control over the auto gearbox.  Auto trans often shifts, dropping torq and losing momentum.  Giving us this option to hold the truck in 1st, 2nd, or even 3rd gear through mud and on hills would beneficial.