I have actually gone to see the conditions of auctioned cars. Some were in abandoned state - a lot of dried leaves, dusty. Like you said - maintenance is suspect, car trashing is also possible.

The other main issue for me - one wouldn't know if the car auction operator/worker swap out the parts (the car could be a 2 year old car, but swapped with bad/older parts), the new owner have to do a lot of repairs, so generally I will avoid auction cars. Usually no original car keys too.