You can just do vehicleid.setScale("x y z");. To get an object's id, look at it and type /getid.
However, if you want an event (I haven't worked much with them):
//Not tested
function Vehicle::setSize(%v, %scalex, %scaley, %scalez, %client)
{
//Idk if we need a client obj here. Maybe?
%v.setScale(%scalex SPC %scaley SPC %scalez);
}
registerOutputEvent("Vehicle", "setSize", "vector");
This hasn't been tested, and I also don't know if you need a client object or not, but go ahead and try it. The event will have 3 boxes at the end, just type in the scale. I'm warning you though - if you do this on a jeep, scales can get quite large, and make Blockland drop fps like hell.
