I found a 2006 used Honda Civic with only 4500 miles for sale for ~$3000 under book. Quite the deal BUT, it had been in an accident at 3000 miles (left front quarter panel) and a non-Honda battery made me look further. There was “staining” (rust color on metallic surfaces) on several engine components and even some corrosion of the paint on the frame below the battery location.
Should I buy it or not?
It sounds as if there was significant damage to the car (enough to destroy the battery). Why is the seller getting rid of it???
I would pass on this car.
It is quite possible the battery cracked and leaked its acid. That is not enough to deter me from the purchase. It is the collision damage that needs to be carefully reviewed. Take this car for a high-speed drive and then let your mechanic have a go at it.