Police have released CCTV footage of an unbelievable road rage crash in Sydney’s south.

The video shows a black BMW slamming into a Holden Astra inside the M5 tunnel in Arncliffe.

The horrific incident occurred in October last year.

Before the crash, police allege one of the men in the BMW threw a crowbar at the Astra when both cars were stopped at a set of traffic lights.

The man who allegedly threw the crowbar hasn’t been caught and is described as a Caucasian man with blonde/brown hair, around 20 years old.

Anyone with information is being urged to contact Crime Stoppers on 1800 333 000.

Click PLAY to watch the shocking crash