Nothing to do with me, I just found it and wanted to share:
https://www.ebay.co.uk/itm/383900963807?hash=item596247d3df:g:XQkAAOSwF41exwRo
It's a special tool for fitting the plastic bumper skin onto the bumper beam without causing any scratches!
What a relief, now that you've come out, someone to share my dirty secret with... voyeuring VW special tools on eBay.de