What's "interesting" to one person may not be "interesting" to another person. Who is to say which vehicles are included and which are not? It's all relative. Don't be a wiktator (wiki dictator). "Top Gear" is a vehicle-specific show so of course it will have a huge list of vehicles. Who is to say that obscure Nissan Datsun pickup truck isn't interesting to someone who finds it fascinating it was shown in a specific episode of a specific television series, for example? Maybe it was someone's first vehicle and, combined with, say, a fond memory of watching that particular episode, it sparks certain memories?

If the site can't handle huge lists it isn't designed well enough and should be redesigned because it's only going to get more vehicles, not less. Databases should be able to expand and grow with ease if they are designe competently initially. Perhaps moving towards MediaWiki would be a better platform, like the Internet Movie Plane Database uses.