Smog Stickers

I admit I don't know the exact regulations, but it's mainly used to keep German-registered tractor trailers, farm equipment and older automobiles out of the city centers. Because you obtain the environmental sticker when you register your car in Germany (as opposed to the Austrian and Swiss vignettes, which you buy at the border), I don't believe it applies to foreign-registered vehicles, or at least, two axel passenger vehicles. You can be close to a 100% certain that any car you would rent in Denmark would meet German emission standards.

But then again, there's the issue of the substantial drop-off fee you'll incur for renting a car in one country and dropping it off in another...

So lets talk about drop fees from one country to another. A few years back we rented a car in Oslo with a reservation to return it in Bergen. Same country, fine. Then the Norwegian air traffic controllers went on strike and flights were canceled so we had to drive back to Copenhagen to catch our SAS flight home. We called Hertz and they said fine, drive back to Copenhagen and you can return the car there. We were not extending the rental period, just returning in Denmark instead of Norway where we picked it up. Cost $500.

I suggest you look carefully at the drop fees, which are hard to find. And consider picking up the car in Germany. Think of what you will save on the ferry aligned!

Jon, I think you are talking about the unweltplakette, which are environmental stickers (green, yellow or red) awarded in accordance to the manufacture performance of your car in terms of exhaustion pollution. Any passenger car manufactured post-2009 (thus any rental car on current fleets of rental agencies) can get a green sticker and thus drive anywhere.

There is no test to be made on your car, they just take the car registration document, look upon the standardized pollution info on it (according to EU rules) and give you a sticker. It costs something like € 8 and is valid nationwide forever (until the car is disposed of).

You can buy such environmental sticker from some gas stations and car shops. It usually takes 5 minutes for you to take your car registration title, have a clerk find the pollution index on it, check on a database/table and give you a sticker.

Read all about it here: http://www.umwelt-plakette.de/englis_informations.php

I didn't test the theory, but when I was in the Black Forest in 2012, it seemed clear from Lonely Planet that rental cars were exempt from this requirement. Like a Swiss Vignette, I wouldn't pay for a rental car from a "big name" unless it came ready to drive. Hertz and Avis have always told me, at the rental counters, that I can drive anywhere in the countries I told them I'm going to.

The drop charge warning is important. I also wouldn't take a car into another country without disclosing it at my pickup counter. Funny they don't let you write it down in the reservation internet dialog. That would be better for both parties to the transaction.

Nevertheless, all cars driving in German city centres with the regulation in force are required to have an appropriate sticker. I got mine through the post after furnishing photocopies of the car's information.

It may or may not be enforced on foreign cars, although that seems highly non-German, but when I read the law I was happy to spend the small amount of money to comply.

Of course, that is my personal car and not a rental one.

Thank you to everyone for your input on the smog sticker issue, all were very, very helpful. I'm actually flying in and out of Copenhagen, so my return will be to the airport. The price for flying nonstop from Los Angeles to Copenhagen was too good to pass up, plus I've always wanted to see Copenhagen.