In SE Michigan / Detroit metro area, I recommend Automotive Techniques in Novi. I took my 944 there for things I couldn't do myself several years ago, and now that I have a Boxster, I'll be taking it there as well. Just had the car up there a few weeks ago for a clutch and oil change, in fact.
I've never checked with any of the local dealers to see what their prices are like, so I can't comment on how much less expensive Jeff Jones & co. might be, but I've been very happy with the quality of their work.
The shop was recommended to me by several other longer-tenured Porsche owners in the area.
Their website seems to have varying amounts of actual content from day to day, but it does list their phone number. They're on Grand River Ave. in Novi.
https://www.automotivetechniques.net/