Anyone know of a website or book that shows historical prices (say, for at least the past 5 years) of muscle car values?

For a site like the Kelly Bluebook for Muscle or classic cars go to :

http://www.nadaguides.com/

Go to Consumer then Classic cars.

find here,
http://www.google.com/search?hl=en&q=muscle+cars+for+sale&sourceid=navclient-ff&rlz=1B3GGGL_enPH318PH319&ie=UTF-8&aq=t&oq=muscle+cars

watch here for more detail about Muscle Cars.....
www.motorclassic.net