OK, I am a bit of a new commer to the US used car market, at least sort of.
I pretty much moved to Europe in 1985 so have had little contact with cars here since then and back then we didn't have stuff like CarFax, Edmund's, Ebay, CarMax, etc. The old fashioned Kelly Blue Book was about it.
So the first question is how accurate and trust worthy is CarFax.
Many dealers have a link to the free CarFax report on the net. Are those the complete reports? Can they be messed with? And just out of curiosity, how far back do they generally go in terms of model years?

I went to a CarMax for the first time in my life today. Intresting place. Of course I think Saturday was not the best day to go but it seems like a reasonable place to get a reasonable deal on a used car. Not cheap, not over priced and my guess a pretty good bet for not getting a piece of junk.
What I do sort of wonder about though... Besides the basic "Buyer Beware", what are the general thoughts of buying through Ebay?
It seems that late model "typical" cars that get sold through E-bay go for about 5% to 20% less than say at CarMax.