...In Germany it is required to have a standardized FAK (DIN 13164) in the vehicle. ...
For the curious (like me) here's what DIN 13164 calls for:
DIN 13164 component requirements Seems easy to find in Europe, harder in North America (Amazon didn't seem to have any w/o expensive addons).
However, Ebay has a few - here's one (just as an example - I have no experience with this vendor or product:
DIN 13164 kit on US Ebay Backup link, if above link doesn't work