Pretty simple achievement which will unlock during a certain mission in the story.
*** Spoiler - click to reveal ***The mission where you have to retrieve Sia Wah from the warehouse down by the waterfront he will escape in a police car and a chase scene will begin.
It will prompt you to carry out an action hijack which is where you hold
to lean out of the car and once the arrow turns green hit
again. BOOM achievement unlock. Also you can get the Sharpshooter achievement right after by holding
and shooting with
at a cop cars tyres.