Crazy68Dart,
I just found this link for safelite auto glass, and put in the year make and model of your Dart, and they have the rear glass, and I do believe it is nation wide, BUT the glass for the rear window is goung to cost a whopping

$905.00 plus a 6% christmas discount to bring it down to 844.99 not including tax.
The front glass would be $493.68 and with the season discount at 61% it drops it down to $189.05 not including tax. It also goes on to say you may need additional parts of 102.36 for the rubber seal. Keep in mind I had to use my zip code for location so yours may be different.
Heres the link
https://www.safelite.com/sslPages/service.jsp#PART_TYPE_ANCHOR
I would call around to some local shops in your area for your rear window, like I did with my front windsheild on my Dart it cost about $280.00 with seal from a place out here called Discount Auto Glass, I guess there is not much difference in price for the front glass and seal.
Hope this helps