[MattyG]

Well you'd need the following functions to do that, you should be able to work out how to use them from the wiki pages:
https://sampwiki.blast.hk/wiki/IsPlayerInAnyVehicle
https://sampwiki.blast.hk/wiki/GetPlayerVehicleID
https://sampwiki.blast.hk/wiki/SetVehiclePos

For the offset, you could do something like SetVehiclePos(vehicleid, x, y + 5, z)