for automotive use only

A notice/warning placed on lubricants such as motor oil and brake fluid in order to prevent your mother/sister/grandmother from using said chemicals to lubricate her nasty, dry snatch while she's whoring herself out for crack.

When this warning/advice is marked on an object, it means that it should only be used, by you, behind the wheel of a speeding automobile. The higher the speed, the greater the use.