I talked to the president of my local bank about rebuilt title cars a few years ago. My daughter was looking at buying a rebuilt title vehicle, and I wanted to get an idea of how lenders treated them to see how hard we should negotiate on the price. He told me they have a hard cap at 70% of blue book value. Sometimes it's lower than that depending on the situation, but never over 70%.
People get more than 70% of fair market value for rebuilt titles all the time because of scarcity or ignorance on the part of buyers, but they are undeniably worth less than a non-rebuilt title vehicle.