Split completely in half is pretty bad. I've been to my fair share of accident scenes in my years as a cop, but even the worst of them where the cars were almost split still had the front and back ends connected by a few small bits of metal and pipe.
The worst one I ever saw involved two speed freaks (both in the pedal-pushing and drug-taking senses of the word) who jumped the curb and plowed their car head-on into a power line pole at about 85 MPH. The front end was completely wrapped around the stump of the pole, to the point where they had to cut parts of it away before they could pull it off. The impact knocked live, sparking power lines across a major intersection and ejected the driver through the front windshield, narrowly missing the pole himself. He sustained serious but not life-threatening injuries. His passenger wasn't so lucky. We found her in the space in front of the front passenger seat where your legs go - all of her. Most of her bones were snapped or pulverized by the impact, and it literally compressed her into the small space below the dashboard. Needless to say, she didn't survive.
These pics are a prime reason why we need to occasionally remind ourselves that there's nowhere we need to be in that big of a hurry.