The rule is something like: "if the vehicle is primarily designed to carry cargo, it's a truck, and thus you pay 25%", and "if the vehicle is primarily designed to carry people, it's a passenger car and you pay 2.5%". There's pretty much no arguing that a pickup was "primarily designed" to carry anything but cargo--that's what they're for. If you get into that discussion with Customs, you will lose.
That said, I do know of instances where importers have avoided the discussion with Customs altogether (i.e. didn't ask them), and put the HTS code for a passenger car on their paperwork, and didn't get caught. If you hear of someone bringing in a pickup and they say they only paid 2.5%, that's how they did it. I personally wouldn't try it, but it has been done. The truth of the matter is that you are one guy, bringing in one car, and Customs probably wouldn't bother with you. The cases you may have heard about where cars are seized and crushed (yes, they can do that, and with no compensation for you) are usually importing businesses who systemically and repeatedly flaunt the rules to defraud the government, and further, know that they're doing so (i.e. intent).
Disclaimer: None of this should be taken as advice on how to commit a felony. If you get caught, they won't mess around and it's not a slap on the wrist. It all depends on how much risk you're willing to take for a truck. Or you just bite the bullet and pay the 25%.