Some GM trucks did. Also, Honda Preludes came with a 4WS option back in the early 90's.
Honda's, Early Subaru's, Mazda 323 sport turbo with all wheel steering, and as mentioned some models of GMC Pick-up trucks.
The import "Tuner" cars were designed to make the vehicle handle even better while on track duty.
The GMC's were more for ease of access and off road assistance while driving.
I've seen some really simple and relatively inexpensive "Rear wheel steer" kits for off road usage advertised in various truck and 4X4 magazines.
One kit retailed for something like $500.00 all in and was an independent electrical unit with built in pump and reservoir as one unit that you install up and out of the way so that those components don't get ripped off whilst on the trail or on the rocks! The ram, stainless steel over braid / Teflon hoses were I believe Aero-Quip or Russel and had additional rubber lined "P" clips and assorted related components supplied.
The only item the end user was to supply was a "Steerable" rear axle. Or the customer could buy an additional kit to convert their stock rear axle in to a unit which is steerable.
I think that they would be very useful and worth while to have on board.
But I'll be damned... Now I cannot find the link on my computer that shows off the kit!
I'll keep looking though!
Cheers
Ry'