Vibration for the G25 Racing Wheel? (Script)

Hey!

I'm currently working for school on a cargame called "BSZ-Racer". And we have to make it compartible with the G25 Racing Wheel from Logitech. It has a vibration which you can test in the drivers. Now I'd like to access it with my Script. I think the MonoBehaviour.OnCollisionEnter is nice to use but I don't know how to config the vibration.

Is there any Function for that? I heared something about the vibration for the XBox controllers and the mobilephones but not for the PC. It would be nice to get an answer. btw: The Axis (forward, backwards, left and right) is working fine. I'm also using Unity Free ;)

Alex