BM... might as well Coke-Cola and ask them if they can give you the recipe
Of course no one will volunteer that information. As a Porsche dealer you are responsible to the Porsche company and ensuring their products are maintained properly for consumer consumption. not give away family secrets or make changes that Porsche may deem would violate your warranty
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Yes, the official manual is not cheap.. Then again, only dealers and Independents would have the ability to amortize the costs. I know there are some (ie, not sure about 987) but you can download from porsches website a whole bunch of technical info and manuals. I have done this for the 986.