Laguna II PH2 Sta-Nav GPS

I'm not convinced the GPS unit is part of the shark fin on a PH2 initiale.

I think it's a rectangular box with a black front and a silver back. P/N 8200004252

Does anyone have an idea where it might be located within the car because I think mine's faulty.

I get the grey GPS indicator.

And I am familiar with the usual suggestions of plugging an Ebay special into the front unit but I wish to check the connections to the real GPS before I go down this route.

Cheers

Laguna II PH2 Sta-Nav GPS