When you see the title, your mind may reel back to the days of being a kid. Well, those memories are nice, but “marbles” in Car-Speak actually are bits of dirt and/or rubber debris outside of the racing line (which is on the edge of the track). If a car is forced onto the marbles, it will likely lose traction and spin out.
The Unmuffled Auto News 
So in car speak its a good thing to say “you lost your marbles” ?
Yepo!