Board Thread:General Discussion/@comment-6369172-20130813134322/@comment-220364-20130813223721

Depends on your definition of double categorization. Right now the methodology for the infoboxes would be to put the article into the broad, basic category. If it were to be tweaked with a "Type", aircraft, car, tank, thinga-ma-bob-mobile, etc, that broad inclusion would still fit.

As for vehicles listed as items in articles or using the item template, most tile it's a error and just needs to be edited to be fixed.