also, i found myself sitting much happier in my valver when i did see a vti coming the other way. As the valver (williams in your case) looks much more different, people who know anything about cars will instantly think: 'ay! its one of them williams clios, they're well quick!!' whereas i doubt they'd take a second look at a vti (only thing that gives em away is the vti sticker (not even a badge!) on the back.. and a jordan just looks like its on the same level as a 106 quicksilver. Look different but i don't think they look overly sporty, even though they def drive sporty!
Up to you mate, i think the williams looks and sounds awesome, definately more of a head turner than a vti.
PLUS, if you're worried about looking like a chav, then don't get a civic. chavs love civics.