I don't fault you for this of course. I realize you're just quoting the information as you found it. But...no. This is not "correct" at all. Unless it applies specifically to the C-255(or the C-256 which uses it as a parent file).
Other than that, it might be useful for gross estimation purposes. But it's definitely not a "one size fits all" solution. Unfortunately, this is just another case of the internet doing what it does best. Unchecked propagation of mythical false information.
@mudhappy the first part is correct, not with those numbers but when you create a steer that has a simular look as the spintires steeringwheels (no offset etc.) Its correct. Your center of the steeringwheel is most of the time your pivot and those coördinates you have to put in the .xml.
Also that second part could be some kind of constant value of the drivers distance in line with the steer, but I don't know that for sure because this is the first time I see those values. I normally just use the editor and the spintires plugin for notepad to position the driver on my seat.
The first part(if I'm guessing correctly what you mean by that) is pretty obviously correct(swap the Y and Z axis for the XML values). I'm just talking about the "-(0.37; 0.42; 0)" part. Which I'm guessing would be the second part(?). Anyway...that formula is not going to work to position the driver's hands "correctly" on every steering wheel. And Pavel knows this. Or he would have used it for "correctly" positioning the driver's hands on all of his vehicles. Which he didn't. Because, like I said, it really only applies to the C-255/256. Or, if you get lucky, a vehicle that has the driver and steering wheel positioned exactly the same as the C-255/256.
Not to mention the fact that it's the totally incorrect, and bassackwards, approach to doing it. You don't position the driver based on the position of the steering wheel.* You position the driver so he looks like he's seated in the driver's seat "correctly". Then, if his hands aren't "correctly" positioned on the steering wheel, you change the "SteeringWheelPos" values so his hands look like they are positioned "correctly" on the steering wheel. You can also set the "LegsOffset" values if his legs don't look "correctly" positioned.
EDIT: *You can, and it does look better if you do, position the driver so he's "centered" on the steering wheel(regardless of whether or not he looks seated "correctly" in the driver's seat when you do). But that's done with the Driver Pos 3rd value(Z axis). Which doesn't apply to this methodology anyway. But I feel it needs mentioned for clarity.
Bottom line: Whatever it was truly meant to convey was "lost in translation" somewhere along the way. That I can assure you. If you don't believe me...try it. You'll see what I mean.