<p>I have printed a MPCNC machine.  It has a print area of about 30" x 30" and up to 11" tall.  (yes, those numbers are correct).</p>

<p>I found a perfect piece of glass at a garage sale for $5.00 to use as my print bed.  </p>

<p>My problem now is how to heat the glass?  I was wondering if there is some sort of tape that would perhaps mimic what is on the rear window of a car, but I couldn't find it anywhere.</p>

<p>Any ideas or links to something that can get me some progress on my search would be greatly appreciated.</p>

Your best option may be to seek out a silicone rubber heating mat, using those terms for your web search. A quick search on my part shows many resources, some of which are known to the 3d printing manufacturing world, while others are equally suited for that purpose.
Don't bond the heater to the glass. You'll need to replace it when it breaks. Consider to use borosilicate glass for better heat tolerance and smaller chance of breakage. A quick search for such a large size pane comes up empty, invalidating that suggestion.
I've read of some people using water bed heaters for large area coverage, but they may heat the area unevenly.
It could be to your advantage to use multiple heater panels with temperature controls for each one. This would provide more uniform heating although more complex temperature management.
I would post links, but there are so many from which to choose.