Who would have thought there'd be so many things required? I thought people just drove on over without any of these accoutrements.
Continental travel has always been somewhat complicated by the requirements of each country. For example, in addition to the "yellow headlights" rule, now thankfully repealed, France has a rule which requires you to carry a complete set of spare bulbs for all exterior lights. Most European countries have a rule requiring you to carry a red hazard/breakdown triangle. At least one (I can't remember which -- possibly Spain) says that if you need glasses for driving then you must also carry a spare pair with you at all times. Some countries require a first-aid kit and/or fire extinguisher.
Then it gets even more complicated by whether those equipment rules apply to
all cars wherever they're from, or whether they apply only to locally registered vehicles, thus making foreign visitors exempt.
There is supposedly a new-ish EU traffic directive which states that an EU country cannot require a visitor (from another EU country) to carry any more equipment in his car than is legally required in the country in which it is registered, with the exception of a warning triangle. Whether you'd be able to argue about that with a foreign cop in an unfamiliar language is another matter......
I understand that a similar problem was happening in France a few years ago over changes in the insurance rules. It used to be the case that you needed to get an insurance "green card" here to show proof of cover when driving on the Continent. That requirement was repealed, and all British insurance policies must now, by law, provide the minimum legally required liability cover for driving in any other EU country. Apparently though, some French cops were still stopping tourists and threatening them with fines for not having the green card, even though it was no longer mandated.
Either way, your U.K. insurance automatically provides liability cover in Europe so you're all legal, but possibly/probably not fire. theft, or comprehensive unless you request it explicity and pay a small extra premium.
Re GB stickers, they are now no longer required
if you have the new-style (Ugh!) EU-format plates which have the blue "ring of stars" strip and GB on them. I do wonder how widely that rule was ever enforced anyway. I've seen dozens of GB-registered cars in France with no stickers.
Oh, and unlike in the U.K., you will be expected to have your driver license, insurance certificate, registration, etc. with you in the car at all times.