A new study by Carfax shows that the number of flood-damaged vehicles has doubled nationwide over the last five years. Furthermore, massive increases have occurred in states with large populations, sprawling urban areas and those within close proximity to the Gulf Coast. Water can fatally damage a car's most important features—like the electrical and safety systems—causing airbags and antilock brakes to malfunction. Carfax recommends shoppers turn to the information gathered in the company's database and new resources like Carfax Xpert to learn about a vehicle's history.Under the Carfax Buyback Guarantee, cars purchased with Carfax Vehicle History Reports that do not contain DMV-reported incidents (salvage, flood damage, lemon, odometer problems) may be eligible to be bought back from Carfax. In the aftermath of Hurricane Katrina, the auto industry made an unprecedented effort to identify, process and report flood-damaged vehicles, as well as warn consumers about the dangers of flooded cars, according to Carfax. The company urges anyone buying a used car to get a Carfax Vehicle History Report that qualifies for the Carfax Buyback Guarantee and have a mechanic thoroughly inspect the vehicle prior to purchase.