It's unclear to me why there needs to be any biometric information at all, on an ID card for use in a modern country like Germany. A chip-and-pin card with a ID number on it and your name (the latter simply so that you don't mix up your card with that from someone else). All the rest goes in a database.
The police can look up your "Virtual ID card" based on your ID number or from other information (a fingerprint, retina scan, name, etc.). Non-security institutions (other government agencies, a bank, whoever) do so only with your permission... you put your card into a smart reader, confirm with your pin, and your "virtual ID card" is shown to the person confirming your identity.
All access to the system is logged (including the police) so that the user can see who's pulled up his info.
The police can look up your "Virtual ID card" based on your ID number or from other information (a fingerprint, retina scan, name, etc.). Non-security institutions (other government agencies, a bank, whoever) do so only with your permission... you put your card into a smart reader, confirm with your pin, and your "virtual ID card" is shown to the person confirming your identity.
All access to the system is logged (including the police) so that the user can see who's pulled up his info.