During the roadtrip my GPS was starting to fail more often than previously. Before I attributed occasional loss of signal to the weird positioning of the antenna (as the car didn't come with a GPS MMI from the factory, there is no shark fin), but it would seem I was just given a faulty one from the get go. It finally gave up the ghost en route to ringmeet with it failing to acquire signal ever since.
One ebay purchase, 5 minute install and 15 seconds of waiting later:
I'm thinking about installing the antenna in a more suitable (for the signal) location, which will require its own video. Right now it's in the same position as the old one (above the fuse box to the left of the main instrument panel).