Had a PPI on a used BMW, Grant Flynn arranged it, accommodated my schedule and that of the owner, did a very thorough job. Grant emailed the results, went through everything carefully with me on the phone, spent a lot of time. He was honest and gave technical opinions without telling me what to do.
This is a **great** choice if you want a detailed evaluation of a car. Can't comment on other services, but rough estimates for repair costs sounded reasonable, considering that BMWs do cost a bit more to repair than your standard Ford or Honda.