You refer to press articles to say no investigations took place. No quotes from the police involved and the reported Germans were Swiss which belies the dodgy registration number.
There are no reports from the 'police involved' for the very simple reason the police didn't bother to get themselves involved until the Berne police said in 2012 that Karsten Mayor has already “all but” been ruled out of enquiries.
Possibly awaiting DNA checks, who knows?
A possible sighting of a missing child in the days after her disappearance were simply ignored, that speaks volumes and it certainly speaks volumes to me about those who condone such negligence.
Your remark about the 'dodgy registration number' is also decidedly odd in my opinion given that it is exactly as the witness reported.
Snip
While their car was a Mercedes Vito people carrier first manufactured in 1996, it had a BE German number plate, which has not been used since 1974.
https://www.euroweeklynews.com/3.0.15/news/on-euro-weekly-news/costa-del-sol-malaga/92470In conjunction with the rest of the witness's report ... how extraordinary is it that professional police officers supposed to be on the alert for a missing child, missed the obvious anomaly of the German number plate and didn't bother to check the sighting out?
Makes one wonder just what else they missed out.