There seem to be two categories of unknown vehicles on the site. Those for which we have a decent picture but have not yet completely identified (but may identify with more searching) and those for which we have absolutely no chance of identifying as to make, model or year due to partial picture, blurred picture, home built customs (including some choppers), etc.

It would seem that we should split the unknown category into two parts:
"unidentified" for those cars that may still be identifed or that only have partial identification.

"unknown" for those cars that everyone has given up on.

We might even run a poll on the forum before we assign a car to "unknown". That may even get folks to visit the forum more.

That would be a good idea. On the other hand, what would it add? Since the newest unknown are displayed first, it is already a little like that. The last page are unknown and the first page are unidentified (as said on the first page of the unknown list, the last pages contain the most difficult vehicles to identify).
And sometimes somebody identify a car that is "unknown" since several months, so I am not sure that it is useful to split them.

Just an idea. I mentioned it only because I am tired of looking for unknown cars to identify that are buried in pages and pages of things for which there is no chance. I agree that some of the real old unknowns may still be identified and like to work on them. The only thing a different category would add might be to clean up some of the clutter on the unknown pages.

We could categorize the completely obscure pics as unidentifiable

Yes. Like we made a "made for movie" make, we could use that for too obscure pictures.
But such category would be useful only for 2-star or more, 1-star vehicles that cannot be identified are maybe not really worth listing, IMHO.

good point, why keep them if we cant do a thing with them, btw the anonymous post above is mine. I could have sworn i was logged in, sorry

In the same way, for the vehicles that have their make identified since long time but that are missing the model, we can remove the unknown and list them with only the make. That's what I do for the make-only vehicles that are unknown for long time.

You could add a "Type unknown" tag, that way people who do know the model/type still can see that they can add information to identify the type.

Further, I think it is good to still maintain the unknown category, new members sometimes add usefull information, so that a type still can be identified. I think it is good keeping them, even if the pictures are not that great....

What do you mean by "tag"? An hidden field that makes the vehicle appear in an "unidentified" list? The problem is that some vehicle may not really need a model name, some others will need year to be fully identified (mostly US cars), etc.

Yes, I see and that wouldn't really solve the problem...