Killing a car without evidence?

well you can drive it til it overheats after removing the antifreeze but he'll know whats up if you feel confident he wont pull apart the motor you can put metal shaving in the oil that will work prob in 2 days you can also drive it on less oil for example take about 2 quarts out and drive this could take awhile maybe about 2 weeks - whenever you can seize up the motor and your prob wont beable to tell cuz it will mix with the antifreeze