History of General Motors GM Credit Ratings

I found a site that has a history of the credit ratings of GM from the ratings bureaus.

Here are the ratings actions for Standard & Poor's on GM
Date --  action
Nov 1981 -- Lowered AAA/A-1+ to AA+/A-1+
Nov 1986 -- Lowered AA+/A-1+ to AA/A-1+
Dec 1987 -- Lowered AA/A-1+ to AA-/A-1+
Feb 1991 -- Lowered AA-/A-1+ to A/A-1
March 1992 --  Lowered A/A-1 to A-/A-1
Feb 1993 -- Lowered A-/A-1 to BBB+/A-2
Oct 1995 -- Raised BBB+/A-2 to A-/A-2
Jan 1998 -- Raised A-/A-2 to A/A-1
Oct 2001 -- Lowered A/A-1 to BBB+/A-2
Oct 2002 -- Lowered BBB+/A-2 to BBB/A-2
Oct 2004 -- Lowered BBB/A-2 to BBB-/A-3
May 2005 --  Lowered BBB-/A-3 to BB/B-1
Oct 2005 -- Lowered BB/B-1 to BB-/B-2
Dec 2005 -- Lowered BB-/B-2 to B/B-3

The rating was lowered a dozen times in 21 years.   It was lowered 4 times in a 14 month period from Oct 2004 to Dec 2005.    By 2005 they at non-investment grade (aka junk bond) rating levels.   Looking back at this history it seems no surprise that GM ended up in bankruptcy.

In hindsight does it seem like a good investment?   Do you think you'd buy bonds in a company like this with this history of ratings?    Of course hindsight is 20/20 but the ratings history is definitely something to consider when buying a stock or bond.