Have you seen some of the crashes in a JK? Crumple zone? You mean when the front windshield ends up where your head would be? I wouldn't run one without a front A Pillar cage addon at minimum.
Recent Example:
http://uploads.tapatalk-cdn.com/20160321/26e41298a0e5856a7d5dd1c5979ed367.jpg/img][/QUOTE]
Crumple zones are mainly in the front and rear of the vehicle. During an impact, such as a head on collision, the crumple zones are designed to absorb the energy from the collision. If I were installing the cage in a daily driver and the cage affects the crumple zone, I'd probably be think twice about it.