No we are not referring to a ChAV (Chieftan Armoured Vehicle) here, but a creature one level below amoeba in intelligence and usefulness to society.
A CHAV (Council House Associated Vermin) is the modern "yoof". Typically talks a lot of "bling bling" thinks that the Beckhams are the Royal Family and wears a lot of cheap gold dog chains. Known as a 'Chozzie' in Australia.
A definite smoker (after pinching the money off his gran) and loves to drink cheap lager. Gets totally mystified when his chavette (girlfriend) gets up the duff as he has no concept of life in general. Immune to responsibility and being an effective member of any community. Completely polarised within his own Chav clan as he cannot connect with normal people or society due to having conversation skills redolent of a Tourette's Syndrome sufferer.
Not really anti-establishment as that is too much hard work (and requires a brain), only interested in cashing a giro and having a steady supply of fags and booze. Quite often found in The Royal Air Force.
In Scotland a "yoof" or "chav" is commonly known as a Non Educated Delinquent (N.E.D). The East coast Scots term is 'Schemie' and West coast Scots stick to 'Ned'. The drink of choice is Buckfast but they are still all chavs.
In Pole position for young chav of the year is Alfie Patten
See: Chav Towns