You see this all the time:
Our Hero (OH) has finally triumphed over the mob of saber wielding monkey guardians. He blows down the doors leading to the heart of The Evil Mastermind’s (TEM) command center/chamber of love, but when the dust settles, OH is greeted by a loud woosh and the hot exhaust of TEM’s escape pod. Their eyes lock in mutual loathing, and as the pod blows through the ceiling and arcs across the sky, OH can hear TEM’s taunting laughter, because when TEM ordered his escape pod he chose the one with the optional exterior PA system for just such an occasion. Before OH can think of tracking down TEM however, he suddenly has a more immediate problem on his hands: that dreaded soothing female voice announcing “the self destruct sequence has been activated. Eight minutes before total annihilation…”
So, has anything every actually been built with a self destruct system? I can understand the various motivations to do so (destroy intellegence, deprive enemy of captured resources, collateral damage), but given the additional engineering/material costs, has anything been deemed worth the expense? Nuclear subs? Spy planes? Chocolate factories?