What types of vehicles get auctioned?

I’m planning on buying a 01 Honda Civic EX at a local dealership. The car has aftermarket exhaust, rims, and cd-face plate…but the CarFax report showed the vehicle was sold at an auction, which makes me wonder: with a nice car like this, why would someone put it up for auction in the first place??? Other than it being a repossesed vehicle (CarFax gives it the buyback gaurantee by the way–not a junked/salvaged) does anyone know why this car could have been sold at an auction? Thanks!
All very valid points!