How do I fit my Towing cover?

Having recently purchased a Bailey and paid for it in full, I was very disappointed to discover that it only had ONE awning rail on the nearside which would be OK for most people but I use a towing cover which I think is terrific- no more arriving on site with areas behind thre wheels covered in muck and bullets! BUT how do I fit it with one awning rail. When I emailed Bailey about this apparent lack of imagination, they were absolutely steadfast that they had not made any vans without 2 awning rails. When I remonstrated with them and told them that I was the owner of one, the tone changed and they made some pathetic excuse about "the van must have been a demo model or an experiment" RUBBISH! A van with one awning rail is like a lolly without a stick - very difficult to use! So how do I fit my towing cover?