I would try Fleabay matey these racks likes of Fiamma come up now and again but darn expensive i have one on my m/home and had one on my last one to as it goes this one attached to a Fiamma box between them new around £550-600 [personally i cant see the value in them but thats what they cost together new] ..... I had looked for one for my first T4 but couldnt find any secondhand finding that most left them on the vehicle when trading or selling them on, or took them off to put on their next T4/T5 ....
But it will not do any harm to look along with your local free ads papers and Gumtree in your area
rack i use on my Astasraphy and my Scenic before that which was at one time also fitted to my Ducato vans rear door very simply to permanantly mount it to the door [in the same way as my current one is permanatly mounted to the rear of my T4 Autosleeper motorhome]although it does sadly require drilling through the door 
and a few brass pipe fittings around £20 from B&Q [and other diy outlets] you can have one similar in design and use for a fraction of the cost 
