No colliding vehicles

Can somone give me a quick function to no collide vehicles?
Thanks for any help.

Use that and check to see if both entities are vehicles, then return false.

Nevermind, my mistake.

i added this to a lua but doesnt seem to be working :confused:

local function ShouldCollideTestHook( ent1, ent2 )
	if ( ent1:IsPlayer() and ent2:IsVehicle() ) then
		return false
hook.Add( "ShouldCollide", "ShouldCollideTestHook", ShouldCollideTestHook )