Hi can anyone help??I recently test drove a 2006 ford focus 1.8 tdci sport, when driving and on acceleration it was making a loud noise as though sucking in or blowing air under the bonnet, i recently drove my friends car 'similar car' an this noise was present but very much quieter!! Dealer said would look into the problem an then arrange another test drive. But i dont want to get hit with a large bill after purchase.. justin.