What Are the Telltale Signs of Flood Damaged Cars?

With Hurricane Ian damaging everything it's path including automobiles, what are the telltale signs consumers can check to see if a used car was in a flood without a mechanics inspection? Yes, of course you should get all cars inspected by a mechanic but if I can look for known signs of flood damaged cars I can avoid paying a mechanic hundreds of dollars. This happened to me once where a loan mirrored on my credit file, a mortgage loan when the servicing was sold and it showed not one but two active mortgages for the identical amount of money onMy credit file. The 20 points though should correct over time because the former servicer at some point should in fact report properly that information they have on you