Carbon Motors Corporation is a newly-created entity that is designing a purpose-built police car, not a modified regular production car. Where we are presently accustomed to seeing the Ford Crown Victoria, the Dodge Magnum, or the Chevy Impala, Carbon Motors wants us to see the Carbon Motors E7.
On the surface the vehicle does not look dramatically different from current police cars, but it incorporates a number of innovative features and notably, a diesel engine. If your immediate reaction is to think that diesels are slow, perhaps you need to be reminded that in recent years diesel-powered race cars have won the 24 Hours of Lemans endurance race. The Ford Crown Victoria is a older design, and both the Dodge Magnum and the Chevy Impala have their limitations in police use.
SUVs have been used by many departments, but these vehicles also have their limitations. Carbon Motors has made a big promotional effort and has a dramatic web site, but it remains to be seen whether the company will be able to bring their vehicle to a police agency near you. You can see the prototype E7 at http://www.carbonmotors.com/