I don’t recall the 60K figure. (I am a Tier 1 supplier engineer and we supply to the Volt.) It may have been tossed around in the media at some point, but not in supplier volume planning numbers to the best of my recollection.
I read it in an article from 2009, which included quotes from GM officials indicating the ‘first generation’ Volt, to be released in 2010, was forecast at 60,000 units. Every other sales figure used in the article was expressed in units/year.
I wondered while reading the article if they had not switched to TOTAL sales forecast when discussing the Volt, since they used the term ‘first generation’ instead of simply using the model year, but that would have been a deceptive thing for them to do, would it not?
"Last week, General Motors CEO Dan Akerson stated that he intends to sell 25,000 Volts this year, followed by 120,000 units in 2012. The optimistic figure for next year is double the original 60,000 units forecast, while the 2011 increase looks astronomical compared to the original expectation of 10,000 cars."
...from a January 26, 2011 article at www.autoevolution.com.
http://www.autoevolution.com/news/chevy-volt-sales-expectations-might-be-optimistic-30238.html
So, apparently, not even GM knows how many units they expect to sell...