I think some options e.g. paint colour, trim etc are included on the sticker with the VIN. Other than that I think you would need to contact Porsche in Germany. I think each country keeps details of the cars registered in their own countries.
By the way, not all Bilsteins are green. Some are yellow. If you are not sure what make they are you could find the part number on them, phone an OPC and ask them what the part is. They should be able to look it up on their system. The original Sport Bilsteins have a number of:
Front:
R36-5001-SPTRear: B46-0975
Cheers, James
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