A small, often outdated, hatchback car that has been given the full 'chav' treatment at Halfords or other trim shop. Fake HID bulbs, skirts 'n' spoilers, cheap alloys, Kenwood or Alpine window stickers (but not necessarily a stereo of the same name!), the obilgatory big-bore exhaust, blonde slag passenger, dickhead with Burberry cap at the wheel. In short:- More wattage than horse-power!
The Nova or Saxo that always races me up the M62 on-ramp and has used up its first 4 forward gears before I leave second!