I've bought cars off copart before, they usually disclose what the primary damage is, particularly if there is undercarriage damage. They also usually disclose if it is a flooded car. Like people said you could pay for a carfax/carproof or whatever it is now called in the US and see if that helps. You can actually also pay for a comprehensive report, it only gives you a bit more info, but you can ask for a video of the inside and undercarriage etc. That being said, I would never buy a car without seeing it.