There is some question about exactly how Volvo did the ad, and there has been some suggestion that they used timbers to shore them up. Check the archives, I believe there was a poster who actually claimed to be present when the ad was produced. I don't recall if he confirmed or denied the story. They did need to shore up the 240 roof for the "Big Foot" ad. (This commemorated a monster truck show where the monster truck crushed everything but couldn't crush a junked 240. It actually happened, but Volvo couldn't manage to duplicate it!) That ad was pulled.

In any case 240s are among the safest of the era they were produced. Volvo later reinforced the "B" pilars of the 7xx, that became the "Side Impact Protection System (SIPS)". They're relatively safe, but there's no titanium or carbon-fiber in the structure - you're still not immortal in one.

-Bill D. Cat