wiper blades

[mikes2]

I'm needing new wiper blades for my 2003 D2 S8.

I got some in Germany last year and they're not clearing the screen very well now.

Does the passenger side need to be a curved blade or does a flat blade work just as well.

Had a search but can't find the definitive answers, what length are they ?

I don't want the aero style so any suggestions ?