The term gets 200,000,000 results on Google. I guess it would be targeted towards car companies selling hybrid/electric vehicles.
Here are some very recent articles where the word "plug-in" was mentioned in the title:
http://news.cnet.com/8301-11128_3-10200328-54.html
http://news.cnet.com/8301-17912_3-10199961-72.html
http://www.msnbc.msn.com/id/29766260/
http://www.usatoday.com/money/industries/energy/2009-03-15-plug-in-electric-cars_N.htm
http://www.autobloggreen.com/2009/03/05/tokyo-preview-mitsubishi-plans-to-debut-plug-in-hybrid-concept/
http://www.californiaprogressreport.com/2009/02/stimulus_bill_b.html
http://blogs.edmunds.com/greencaradvisor/2009/02/economic-stimulus-act-contains-good-news-for-green-car-advocates.html
http://www.usatoday.com/money/autos/2009-02-02-ford-plug-in-hybrid_N.htm
http://greeninc.blogs.nytimes.com/2009/01/11/toyota-plug-in-hybrid-coming-late-this-year/
http://latimesblogs.latimes.com/uptospeed/2008/09/chrysler-electr.html
Look good at all to anyone?
Here are some very recent articles where the word "plug-in" was mentioned in the title:
http://news.cnet.com/8301-11128_3-10200328-54.html
http://news.cnet.com/8301-17912_3-10199961-72.html
http://www.msnbc.msn.com/id/29766260/
http://www.usatoday.com/money/industries/energy/2009-03-15-plug-in-electric-cars_N.htm
http://www.autobloggreen.com/2009/03/05/tokyo-preview-mitsubishi-plans-to-debut-plug-in-hybrid-concept/
http://www.californiaprogressreport.com/2009/02/stimulus_bill_b.html
http://blogs.edmunds.com/greencaradvisor/2009/02/economic-stimulus-act-contains-good-news-for-green-car-advocates.html
http://www.usatoday.com/money/autos/2009-02-02-ford-plug-in-hybrid_N.htm
http://greeninc.blogs.nytimes.com/2009/01/11/toyota-plug-in-hybrid-coming-late-this-year/
http://latimesblogs.latimes.com/uptospeed/2008/09/chrysler-electr.html
Look good at all to anyone?