I have a friend looking to buy a used (new to her) car. I may be going down that same road in the next year or two. I had a pre-purchase inspection on the stang, which identified the leaky diff, which was great. But that was in the burbs, and this will be on the north side of Chicago, in the city. Anyone have any recommendations of shops for a pre-purchase inspection? Price would be helpful as well, but I imagine they're all similar, and I can always ring them up.