Citing overwhelming demand, OnStar has announced plans to offer an aftermarket version of their popular telematics service.

Citing overwhelming demand, OnStar has announced plans to offer an aftermarket version of their popular telematics service.

Consisting of an advanced rearview mirror, the retail version features Automatic Crash Response, Turn-by-Turn Navigation, Stolen Vehicle Location Assistance, hands-free calling, and one-button access to emergency and roadside services. More importantly, it is certified to work in 99 percent of the top 20 selling non-GM vehicles made in the past 10 years (approximately 55 million cars and trucks).

On sale this spring, the mirror will be sold at Best Buy and other select retailers for $299 (installation is expected to cost $75 to $100). Of course, to get service, you'll need to fork over an additional $199 a year.

In related news, OnStar is launching a pilot test of their voice communications app for Android smartphones. As we have previously reported, it will enable drivers to send and receive text messages as well as update their Facebook status via voice commands.