Look at the prices of new trucks, then at the median salary. People should not have car payments that rival a small mortgage, yet they do.
Generally it's something along the lines of "a truck or van registered to a business is assumed to be a work vehicle, so pays less tax than a passenger car".
Of course you need to have a business to take advantage of that loophole, but it doesn't need to be a business that actually has any use for the truck- it could be a one-person IT consultancy.