Fuel-powered mobility scooters that resemble a car were allowed to be registered as new vehicles until August 2002. These vehicles still enjoy grandfathering protection (according to transitional law FeV §76) and may continue to participate in traffic.
You do not need a driver's license!
This regulation is legally anchored (§76 FeV).
But: It only applies to certain vehicles officially approved as 'Other motor vehicle mobility scooter'.
Important:
A normal vehicle that has been limited to 25 km/h, or has papers stating 25 km/h, or the papers are green, does not automatically become license-free! Neither do 45 km/h cars.
If you buy a car/moped car without the correct papers
or own and drive it, then the following applies:
1: Driving without a driver's license: heavy fine.
2: You are not insured; all damages are your responsibility.
3: You paid way too much for a car/moped car that is actually worth much less.
To be allowed to drive without a driver's license, you need the following documents
Original operating permit (Green wax paper) from TÜV.

"Green papers" is the term for the original operating permit ("green wax paper") of a mobility scooter that is approved for use on public roads and is in possession of the correct registration documents. "Green wax paper" is the original document that allows the use of a mobility scooter without a driver's license, as it proves the vehicle's compliance with the applicable regulations.