The former Melbourne biker gang leader Amad “Jay” Malkoun has been seriously injured in an apparent car bomb attack in Athens.Malkoun, who was previously Victorian head of the Comancheros, was trying to start his Mercedes outside a gym in the upmarket suburb of Glyfada on Friday when the blast occurred.Four other cars were scorched during the explosion and the 56-year-old was rushed to hospital with serious but non-life-threatening injuries.The bomb blast was close to where Sydney gangland…