Driving Germany to Benelux
 

Can anyone advise about driving from Germany to Benelux countries? I find the information on "stickers" and "parking tags" to be very confusing. I will likely be driving from Kaiserslautern to France, Luxembourg, Belgium, possibly Netherlands.

If you drive into a city in Germany your car will almost certainly need a green umweltplakette. If it is a hire car it will already have one.

No idea what you mean by parking tags, you park in a car park and pay for it if required, as in the rest of the world, unless it is a blue zone (in the Netherlands at least) in which case you need a parking clock which you set t your arrival time and you can park for free for a maximum amount of time, which varies depending on the town.

A parking clock being a piece of cardboard with a clock face on it and movable hands. As hetismij2 says, upon parking, you set the clock with your time of arrival and put it in the front window of your car. A nearby sign should tell you how long you can park there.

Here everything you must know about a parking disk:

https://en.wikipedia.org/wiki/Disc_parking

You rental car will have such a disk anywhere inside, maybe in the glove compartment. If you arrive at a parking space, switch it to the next half hour, e.g. if you arrive at 10:31, set it to 11, if you arrive at 12:29, set it to 12:30. Then you put it under the windscreen, so that it is visible from outside.

Also, there are parking zones where you have to go to a ticket machine, introduce a few coins, get a ticket and put it in your car under the windscreen.

Traffic violations with a rental car are nasty, because the rental car companies will charge an administrative fee for handling the fine (which is fair enough IMO).

Blue zones alsqo exist in Belgium and France. However I use my disk about once every 6 months.
No stickers in Belgium nor France.