One thing to keep in mind is that a lot of these toys are not scale models; stated scales are often approximations, marketing BS, and otherwise, a determination of the clueless. Most of the die-cast scale toys that I’ve scaled (I’ve probably scaled more than a thousand of them, as we sometime use these as trial exhibits in accident reconstructions), tend to scale to three different scales in length, width, and height. Actually, so do many of the “scale models”, whether die-cast or plastic.
There are die-cast (and other) models that are true to scale, but they tend to be pricey. For example, a couple of construction type die-cast dump trucks that I bought earlier this year (for work) in 1/32 scale retail at about $800 each, which might seem crazy, but they were amazingly accurate, and to scratch build them would have take more than 80 hours each, plus required extensive dimensional detail.
In my experience, a lot of 1/43 scale toys tend to be undersized in length, and too wide relative to their length. For example, I have a “1/43” scale Isuzu Rodeo sport ute (circa 1989) that scales to about 1/51 scale in length, and door thickness and interior tub width is such that two typical “28mm”‘figs could not be placed side by side in the front seats, despite the width scale being around 1/45. Heights tend to be funky due to the types of wheels and tires used with the toys not being close to real tire representations.
My search for true to scale models is much like Rhoderic’s, the range of of available options are much more limited, though they are out there. I tend to be goofy about scale most of the time, but gave up with respect my post-apoc stuff. I just came to accept that my 28mm figs are often larger than stated, and my 1/43 scale vehicles are often smaller than stated.
Regarding trucks, there are a small number of semis and the occasional straight truck in 1/53 to 1/55 scale, though price tends not to be very favorable from a gamer standpoint. Sometimes you can find trucks in these “mid-50s” scales as part of construction equipment lines for Caterpillar, John Deere, etc.