
Mega, CrewMax, Crew, Double
Mega and CrewMax are different names given to the same design by different manufacturers. This cab style consists of four front-hinged doors of equal size. Rear seats have storage space behind them, and the truck bed is on the short side. Crew cabs have four full-sized, front-hinged doors and a full rear seat for daily commutes, group nights out or brief family road trips. Double, which Ram refers to as "Quad," resembles a four-door sedan attached to a pickup bed. The doors have conventional front hinges, and there's a rear seat with a bit of leg room.
Regular, Extended
Regular cab is your classic two-door pickup with no rear seat or space behind the rear seat. Extended cab is notorious for its two front doors, both front-hinged, and its two rear doors with rear hinges. The rear doors can only open after the front doors open, hence the nickname "suicide" doors.