I also don't see the point in all the categories. I like to know at least year and make - model is nice but not really necessary as I can look up all the other stuff.

I don't think that this site can be an exhaustive enclycopedia of car information and it seems that is where we are headed.

In addition, I continue to think that misinformation is worse than no information.

Actually we even have too much categories now. Though that it can be useful for doing searches (the only reason why there are such categories)

True that too many categories leads to compromise/confusion. I don't demand that new categories be installed, just any way to locate cars with specific details. The comments field is very useful, if it could be used in conjunction with the make/model fields. Currently, they are independent (either/or). It is not necessary to strive for a seamless search capability such that a used-car website would have (year/make/model/style/doors/color/seat config/accessories/etc).
This is still an irreplaceable website and community.