Perhaps not _ultra_light, but more or less the same here.
We bought a 2019 Tundra and the GVWR is not technically enough to carry even the supposedly light FWC (they _use_ to be light...our 2020 Hawk shell showed up with a dry weight of 945 lbs). (Also, the 4x4 Tundra has, as far as the sticker on the truck says, way less GVWR than I believe most people will admit).
That gives us just a few hundred pounds before we exceed GVWR. With ourselves, and the 38 gal gas tank, along with propane tanks, and a cooler, we're pushing GVWR pretty hard.
We don't worry about every ounce, like we do for backpacking, preferring a more pragmatic approach, but with every trip (it's still new, we haven't much experience yet) we try to optimize--removing unneeded items, replacing with better, sometimes heavier (real, but light, pans instead of our old stupid, inconvenient backpacking set) and sometimes lighter (we don't need any of this stuff....)
To our shell we've added: 7 gal water jug, and foot pump. DIY counter-top and sink. We use a small two burner camping stove, and a small aluminum table for cooking mostly outside. We have light backpacking chairs (note: our actual backpacking chairs are just for our sleeping pads...so this was a car-camping upgrade as far as we are concerned.
There are no cabinets, all our gear (cooking gear, and dry food) is stored in two boxes and a couple of junk drawer trays under the counter which has one very thin shelf.
Seating is a removable bench (3/4 inch birch plywood, for lightness, with an aluminum stiffener) along the back window. We use the bed's cushions for that.
It's both incredibly spartan, but also, what's missing? Nothing as far as we can tell.