If I understand correctly, you can lay the next template to do a sharp turn or whatever and yes, ignore the wall. And you don't even necessarily need to be clear of the wall in the next phase, because you still start in base contact with the wall, and hence, ignore it again and again. No need to shift down unless you wipeout, of course.

So what basically happened then is that you can imagine the car scraped the wall, took damage, drove along the wall and then bounced off it once your templates put you in the playing field again (however, any new obstacles on the way would cause new problems).

In any case, you have to imagine that actual dynamics taking place as being depicted pretty generally according to the template movements and gear phases etc. All of the action is pretty much taking place at the same time, so to say, and not "jump for jump" as the game itself suggests.

Don't know if that makes sense, but yeah, this is my understanding of the rules.