This applies to the 2013, but may apply to 14-15's as well. DC1 will include the rear bumper park sensors and rear camera, DC2 includes the front facing camera in the windshield and also front bumper sensors. Those are the easiest way to determine if those safety packages were installed from a glance, particularly since most sellers don't include pictures of the steering wheel buttons. If it happens to have an image of the center radio stack, it will show a NAV button if it includes navigation, and will also include the Bose option (required for NAV). Heated seat options will also be obvious in the radio stack picture as it shows the seat controls just below the temp and fan speed controls. Of course leather will almost certainly be obvious unless it's got the beige interior in which case the leather option is a blend of leather and suede.
There is another post on here that shows how you can determine if the car has leather/nav/enhanced emissions based on VIN which can be helpful if you're looking for one, some or all of those options but unfortunately doesn't indicate any of the DC 1/2 options.
post #3
https://gm-volt.com/forum/showthread.php?14347-What-Volt-do-I-own
There is another post on here that shows how you can determine if the car has leather/nav/enhanced emissions based on VIN which can be helpful if you're looking for one, some or all of those options but unfortunately doesn't indicate any of the DC 1/2 options.
post #3
https://gm-volt.com/forum/showthread.php?14347-What-Volt-do-I-own