To add to what others said, it used to be that the absurd pickup trucks were all customized. Someone would take a truck as produced and sold by the manufacturer and add "lift-kits", maybe modify fenders, and add huge wheels and tires for some off-road purpose. Or just for the image of some off-road purpose. These would not always be street-legal but there wasn't much enforcement and it wasn't a high percentage of all the vehicles on the road.

Trucks roam the streets today, in their factory configuration, that make those lifted 4x4 trucks from 30-40 years ago seem like reduced scale toys. It's madness. The most cartoonish, distorted adolescent fantasy proportions have been mainstreamed and normalized over decades. It's a Truck Body Dysmorphic disorder.

As in, off the factory floor, before even considering aftermarket lift kits or other modifications.

I believe the most common definition for this context of "production" is "mass produced commercial vehicle"

as opposed to DIY go karts and handcrafted hypercars of course

Not op, but in this context, it likely refers to mass-produced vehicles with stock configuration.

Vehicles in production for mass market consumption.