[Nero_3D]

Try it with OnPlayerUpdate, if that didn't work try it with the inverse velocity, that should move him constantly forward and backwards (no clue if that actually works)

pawn Код:

new
    Float: vX,
    Float: vY,
    Float: vZ
;
GetVehicleVelocity(vehicleid, vX, vY, vZ);
SetVehicleVelocity(vehicleid, -vX, -vY, -vZ);