How do we value our cars?

Never been a fan of it but how about an appraisal? A bit late for it in the case of the op but.....We have our car insured for roughly what I have in it right now. When we first insured our 64 Fairlane we had no idea what to put the value at.....Spoke with Haggerty and there suggestion, being that we had just purchased it was to insure it for the purchase price plus what it cost me to go get it from another state. Made sense to me at the time....