Rain and drip guard for Omnistor 5 series

We have a van conversion motorhome with an Omnistor 5 series awning.  The brackets are fixed to the roof of the van which leaves a sizeable gap between it and the motorhome roof so rain drips onto kitchen and worksurface when the sliding door is open.  A Fiamma rainguard won't work and neither will Omnistor's own rain sheld.  Has anyone else a similar problem and if so have you found a solution?