Start this in parallel with customs
The Datenblatt has the longest lead time of anything in this process — 1 to 6 weeks. Request it at the same time as your customs declaration, not after.
How to make the request
Locate your VIN (17 characters — bottom corner of the windscreen, driver’s door frame, or vehicle documents). Then write to the official German importer:
Subject: Datenblatt für § 21 StVZO Einzelabnahme — VIN: [...]
Include: VIN, make, model, year, purpose (individual approval § 21 StVZO).
If the manufacturer goes quiet
TÜV↗/DEKRA↗ can often source the Datenblatt through their own industry channels, for an additional fee. This is the path of least resistance when direct requests fail.