I think it's safe to assume that most people play Battlefield 3 because of how bat-shit crazy it is. Sure, it's a competent shooter and all that, but the majority of the fun to be had is from crashing Jets into the streets or driving tanks through buildings. I have always preferred this series over Call of Duty for those very reasons.
The guys over at 1080 Pixel Gaming have captured footage of a successful attempt they made in getting a tank to explode its way on top of a roof. In the YouTube comments section, they said they used about 60 things of C4, so know that if you try to do it yourself.