Yes, you are right, it has to be lowercase e, now it works like a charm
Thank you all for help!
Final product:
function enterVehicle ( theVehicle, seat, jacked )
if isPedInVehicle (source) and getElementModel (theVehicle) == 478 then
setVehicleHandling(theVehicle, "mass", 1050.0)
setVehicleHandling(theVehicle, "turnMass", 2000.0)
setVehicleHandling(theVehicle, "dragCoeff", 3.3)
setVehicleHandling(theVehicle, "centerOfMass", { 0.0, 0.1, -0.25 } )
setVehicleHandling(theVehicle, "percentSubmerged", 75)
setVehicleHandling(theVehicle, "tractionMultiplier", 0.65)
setVehicleHandling(theVehicle, "tractionLoss", 0.85)
setVehicleHandling(theVehicle, "tractionBias", 0.5)
setVehicleHandling(theVehicle, "numberOfGears", 4)
setVehicleHandling(theVehicle, "maxVelocity", 130.0)
setVehicleHandling(theVehicle, "engineAcceleration", 8.0)
setVehicleHandling(theVehicle, "engineInertia", 3.0)
setVehicleHandling(theVehicle, "driveType", "rwd")
setVehicleHandling(theVehicle, "engineType", "petrol")
setVehicleHandling(theVehicle, "brakeDeceleration", 6.5)
setVehicleHandling(theVehicle, "brakeBias", 0.5)
setVehicleHandling(theVehicle, "ABS", false)
setVehicleHandling(theVehicle, "steeringLock", 35.0)
setVehicleHandling(theVehicle, "suspensionForceLevel", 1.15)
setVehicleHandling(theVehicle, "suspensionDamping", 0.1)
setVehicleHandling(theVehicle, "suspensionHighSpeedDamping", 0.0)
setVehicleHandling(theVehicle, "suspensionUpperLimit", 0.14)
setVehicleHandling(theVehicle, "suspensionLowerLimit", -0.1)
setVehicleHandling(theVehicle, "suspensionFrontRearBias", 0.55)
setVehicleHandling(theVehicle, "suspensionAntiDiveMultiplier", 0.3)
setVehicleHandling(theVehicle, "seatOffsetDistance", 0.25)
setVehicleHandling(theVehicle, "collisionDamageMultiplier", 0.70)
setVehicleHandling(theVehicle, "modelFlags", 0x40002804)
setVehicleHandling(theVehicle, "handlingFlags", 0x4000001)
setVehicleHandling(theVehicle, "headLight", long)
setVehicleHandling(theVehicle, "tailLight", small)
setVehicleHandling(theVehicle, "animGroup", 1)
--outputChatBox("Handling changed successfully !")
end
end
addEventHandler ( "onPlayerVehicleEnter", getRootElement(), enterVehicle )