There are rough plans of the Desiro units here https://assets.new.siemens.com/siemens/assets/api/uuid:0ac7caed-001a-428f-a08c-5d9ec43a4afd/datenblatt-desiro-2018-rrx-d.pdf, I can't seem to find any of the normal dostos.
The Desiros are 4 coaches each, thus 2 single deck end vehicles and 2 double...