Feature suggestion: Allow a discussion forum on each car model. For example, my 2002 Nissan Maxima has a few quirks that I would like to discuss with fellow '02 maxima owners -- like the weird tendency of the MPG gauge to overestimate mileage. This would create a community around each particular car model.
Great suggestion. We have this in our plans, and we've been discussing how to make it happen on the site.
There are dozens of car forums across the web devoted to discussing specific models—and you can probably find a Maxima forum somewhere with a Google search. But I think model-specific forums could still be useful here because the focus is on mileage, and you have lots of Maxima owners interested specifically in mileage issues gathered in one place.