CarShield essentially outfits older cars with a security and diagnostics system akin to OnStar or BMW Assist with a small adapter. By plugging CarShield into the diagnostics port of any vehicle manufactured since 1996, it can access the vehicle's computer system and transmit data to a phone or Internet-connected device using cellular technology. CarShield monitors the car's battery and heat level and can detect other problems like oil pressure and tampering with the CarShield unit. The integrated GPS also provides for vehicle tracking, and CarShield can be configured to provide updates or alerts about vehicle status over e-mail or SMS [source: CarShield].
CarShield is one of the less expensive examples of telematics on the market today. Telematics refers to the field of telecommunications and informatics -- the long-range communication of data about a car. If you own a car manufactured post-1996 and want to enhance it with telematic abilities, CarShield costs $349 and requires a $159 annual fee to cover the system's wireless services and roadside assistance. Just like OnStar, CarShield has advisers who can provide emergency assistance. CarShield was a finalist for the 2010 Best Aftermarket Device Telematics Award [source: PRLog].