Any way to script car or compile it that way so it slows down on specific surfaces?

[TheSyntaX]

Hey, is there any way to compile or any $keyvalues commands that would make rigged car slow down or drift on specific surface? I compiled car and made it work, tested on my F1 track map and to be honest I think players will take shortcuts on it driving over gravel since it has no impact on speed.
Here is what I mean basically:
[media]http://www.youtube.com/watch?v=3k7B3tQ5Lj0[/media]

[fury_161]

I don't think that would be a keyvalue, I think that is something you should setup in the map.

[TheSyntaX]

[QUOTE=fury_161;30161301]I don't think that would be a keyvalue, I think that is something you should setup in the map.[/QUOTE]

Oh damn. Ok thanks anyway.