Nyancle racing level 4

In level 4 there are some kinds of roadblocks (walls) which are either white, red,green or checkered and have letters on them (a, b,c and x) Does anybody out there know how to get past them without being damaged???

So ramming into them and going on is not the option I'm looking for...

Thanks in advance for any help!

Never mind; I figured it out myself. There apparently are certain spots in these walls through which you can drive without being damaged.