Possible to install OnStar in 2000 Jimmy SLT?

I've recently purchased a 2000 Jimmy SLT and am loving it. It did not come with OnStar, though I know that some vehicles had the OnStar system (possibly Jimmys) as early as 1999.

I'm wondering if it's possible to install it in my truck. I know it may be a fairly intensive modification, but it's something I'm willing to look into.

Thanks in advance from all who reply!

Mark

I also have a 2000 jimmy and it has a factory onstar system in it i do not have it hooked up but it does work, all of the internal componants are in the back right hand(as looking from the back) side panel along with the amp for the bose system, if so equipped and the buttons are on the rearview mirror, there is a mic on the glass by the mirror and a small speaker by the drivers head on the left hand side. good luck