Racing Game Boundaries - Acting weird!?

Okay check out what I’m working on.
http://media.putfile.com/Untitled-Uber-Racing-Game-TEST-1
The graphics are open source, so don’t nag if you’ve seen em before.
Try the game I posted, you will notice that when racing at high speeds, you can get stuck inside the boundaries! :asleep:
Here’s the boundary code I’m using. I don’t care that the car overlaps the boundary, I’m just worried about players getting stuck.


      y = (Math.cos(Math.PI/180*_rotation))*_root.speedHolder;
x = (Math.sin(Math.PI/180*_rotation))*_root.speedHolder;
    if (_root.land.hitTest(_x+x, _y+y, true)) {
        _root.speedHolder *= -.1;
    }

_root.speedHolder is the current speed of the car. This script is inside of the car movieclip. _root.land is the track boundaries. What can I do to fix this problem?

Thanks,
/craze3