1. Open Editor
2. Place player and a empty vehicle
3. Preview
4a. Enter following for the player into the Debug Console:
player addEventHandler ["GetIn", {titletext["it works","PLAIN"];}]; - this will not work
4b. Name your vehilce "TestVehicle" and enter the following into your Debug Console:
TestVehicle addEventHandler ["GetIn", {titletext["it works","PLAIN"];}]; - this will work