I've recently took over the job of conservator for an individual and I'm assessing their assets. One issue I see is that a used vehicle sold to them was overpriced and that the bank here in Michigan should have never authorized a loan for the amount it was sold.

To assess whether this is the case I need to know what the Blue Book value of the vehicle was when it was sold in 2011. I know how to find CURRENT blue book values, but I'm having issues searching for PREVIOUS blue book values. Any links or help would be great.

Do not link just to KBB.com unless you have directions on how to find the blue book value of previous years.
It is 2007 Chevy Uplander LS (base model, no frills) and had about 40k miles on it when it was purchased.