Hello...
Guys, when I built my Cobra I was under no misconceptions what I was getting. I have a 1965 death trap with the skin of a beer can on steroids. If I were worried about crash protection I would have bought an H1. At least that may survive a glancing blow by a semi in a Hummer.
After graduating from High School I placed my fathers Galaxy 500 in front of a city dump truck, which he obligingly his us. My passengers and I all walked away. I don't have any illusions about the outcome were I in the Cobra.
For may years I rode a bike. I also have a CJ5. Neither one would fair to much better in a side impact. Although the roll cage on the jeep might protect you in a roll.
Bottom line... Build it best you can, do everything right. Pray that your time isn't up whilst driving.
On the other hand, got to go someway...