Truckzilla
"Truckzilla" is the pet name given by fans to John's truck. It was first coined by LJ user disanddat in a thread in the papawinchester LJ community on the 31 of March 2006. Full thread here
The input for the name came from a TWOP's Supernatural episode recap of Shadow in which "...Daddy walks off to get in his Truckosaurus Metallitruck."
We first see Truckzilla at the end of 1.16 Shadow.
It is also seen in Dead Man's Blood and Salvation. The truck was last seen parked on the corner of Wabash and Lake, outside the warehouse in Lincoln, Nebraska where John went to meet Meg in Salvation.
Truckzilla is a 1986 step-side GMC Sierra Grande. It's almost certainly an automatic and most likely a 4x4. (A definite 1986 GMC Sierra Grande for comparison.) It has a well-stocked weapon's compartment.
