I'm not sure if this is a bug.
Any key is down can work but on key pressed doesn't work that can't set a variable.
<img src="http://gyazo.com/e2f1c2f54975b6e7ef874c932528e551.png" border="0">
Try .capx yourself:
http://flamma-alfa.net/html5game/GetCAR.capx
Should be fixed in next build!
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Good one