Help on editing performance

What i've been trying to do is set the performace so that 2 cars (the Arrows) can't move at all when the lights go out.

I actually did this a few weeks back, but since then i've messed around with a few things. Now I'm using Car Set Creator, and when I set the race powers etc to 0, the two cars still move very slowly off the grid (i'd have the qualify last). Originally they would sit there until moved by the marshalls before the rest of the pack came round, and it worked perfectly.

But now I just can't get those cars to stay!

Any ideas?