I could not reproduce the wall glitch you talk about... and trust me, I tried.
If you are going almost parallel to the wall and hit it going at low speeds while turning into the wall, the front sometimes goes in the wall and you can drive through.
I'm not exactly sure why anyone would be turning into the wall at low speeds, but its still a bug.
*Edit
Also, if you hit a wall and afterwards turn away from the wall the back end will go inside the wall.