I'M kind of getting there but it has been a slow old slog.
I've got eiderdown for 1a but it gives me ? D as the first word for 3d. Clue is Did badly to take vehicle inside pass. 2,4. Can't get it as I don't know any words ?d. It might be a Latin phrase like ad hoc but I don't know any where the last word has 4 letters. Stuck!