[motorstereo]

I find the Bentley service manual is excellent (with some minor quibbles). I also follow advice found on this wonderful forum, and various high quality youtubers like Heidi & Franny, parts classic (spelled w k), Joe Engineering etc .

I also have Wayne Dempsey’s “How to Rebuild and Modify Porsche 911 Engines” and a set of the factory service manuals. All of this is certainly not necessary to maintain your car and any issue you might have these cars has surely been addressed on this forum.