There still under the chassis. They are dirty. I have not checked them up at all. I would think they were high mileage. I will try to take a look this evening when I get home. I don't konw what you mean by flat spots in the center?? Can I see what you are talking about without taking them off the van. I was planning to load it tomorrow to haul it away. Loading with the rear axle off could be a problem.