Not near 15-20 year lows ... look at the chart below and see where it was in the 1983-1988 (15-20 yrs. ago). It appears to me as if it's up 100% since the late 80's.
http://finance.yahoo.com/q?s=GM&d=c&t=my&l=on&z=b&q=l
IMO GM was incredibly overbought then ... of course that was when the...