A car can be described as "a wheeled motor vehicle used for transportation".
An organism too big to be transported by a car and that can use it as food (can digest steel and rubber) would describe it rather differently. What you have described is one of the car's possible uses, but in order to see that use you have to first ask the question: "how can I put this object to use so as to best serve my interests/values?" Not that you ask this consciously, of course. It's just that any possible use of the car emerges only when viewed through your value-spectacles.
You said all this yourself in different words, which makes me very glad cos it means you actually get what I'm saying! My views are rather idiosyncratic so it's sometimes hard for people to understand them.
Also (because maybe the reason you're trying to salvage description is because you're trying to salvage objectivity), note that the idea that objects can't be described purely descriptively doesn't mean there can't be any objectivity. To me, an object is (objectively) the sum of all its possible uses. So when you view the car as a transportation vehicle, you're viewing part of its objective reality: part of its many possible uses. A chair is home and food to a termite; firewood, weapon, and seat etc. to you. Add together all the possible ways a chair can be used, and you got the full and objective description of what a chair really is. More on that in the next installment!