If you have any of the prior California registrations they will have the plate number and once you have that you can go to this site to see what shops did the smog check on the car. It can help you to figure out where the car may have moved around. The shop owners may even know the owner of the car. Here's the link:

http://smogcheck.ca.gov/VEHTESTS/PUBTSTQRY.ASPX

I checked already for you by VIN but nothing poped up. In California they must go through that smog test every other year.

Gute Fahrt mit Ihrem neuen Porsche!

 

Thank you for the replies !

I think, I made a mistake. The VIN should be

WPO ABO 912 GS 12 1010

@Edgy01

I have to ask my friend, if he knows a former registration. Thank you for your idea

Ronald