I travel to Europe once a year (drive through France/Belgium/Netherlands/Germany/Czech Republic) and I must say i can't keep up with the myriad of requirements/regulations.
I too keep a stock of hi-viz vests, breathalysers, spare-bulbs, triangle, first-aid kit, electric tyre pump, etc. but I've never seen a single foreign-registered car or truck with headlight filters attached. Our motorways carry loads of non-UK lorries, do you really think they affix such things each time they're here?
I don't think the police in each of the countries I frequent are sitting waiting for UK motorists, they're as under resourced as ours to be honest, they don't even notice because there are so many nationalities on the roads these days - all over Europe.
The instructions for fitting headlight filters are so complex and vary greatly even between cars of the same model but different years.
Germany will be introducing a new Road-Tax for their motorways, Czech Republic already has it. If you want to drive on the Motorway you have to pay for and display a new 'tax-disc', where and how you're supposed to buy that when you don't live there is beyond me unless they're going to re-introduce border controls, etc.
It's basically why we're better out off OUT of he EU until it sorts its house out properly.
(rant over)