it doesn't make any sense to me. If it was GPS navigation then it was years ahead of its time since back in 94 the hand held units were being made but they really were not making them into car audio yet. It took a few more years for the double din screens to make it really viable. Alpine tried a system called the blackbird that had a stand alone gps you could take with you, or plug into the deck and sometimes it would work. Mention "blackbird" in a longtime alpine dealer today and if they sold them back then they will start to twitch remembering all the problems.
The only other thing I can think of back there in that area is the inertia switch for the fuel cut off and it is possible that the european version required a different version than the US version. I think the US version only detected forward/backward impacts, maybe that does lateral as well? Idunno do ya have the standard inertia switch on the back wall of the trunk with the red dot/switch on top?