Umweltzone sticker for a car that matches restrictions but not age limit

I want to drive my car to the city of Stuttgart. I understand I need an umweltzone sticker for this.

According to ANWB (The place that distributes these stickers in the Netherlands) these are the possible requirements for the green stickers:

• Vehicle needs to be built after 31 december 1992
• Vehicle has emission norm Euro-1, Euro-2, Euro-3 or Euro-4.
• Vehicles with hybrid motors also get green stickers

'No sticker will be provided to cars built before 31 december 1992. If the car is built before this date and does have a motor with emission class Euro-2, you get a red sticker.'

Now, my car, a Porsche 911 964 built in 15 october 1992, goes by Euro norm 2. This model was built until late '93, and if it rolled out of the factory a few months later, it would have gotten a green sticker without any issues.

Now, I need this green sticker to enter Stuttgart. How can I make sure I get this green sticker, since my car passes all needed things except for the building date?