London - Police were last night searching for a driver who deliberately rammed into another car three times, forcing it off the road and killing a young couple. Toby Exley (22) and his girlfriend Karen Martin (20) died after their car crossed a dual carriageway in west London, after the suspected road rage attack. A witness has said that an unidentified second car was following the couple on the westbound carriageway, before slamming into the back of it three times. On the third collision, the car was forced onto the eastbound carriageway where it was hit by an oncoming vehicle. The mystery car drove away after the incident.