Triple seat part query

[Iangooner]

So this isn't mine , but my dad's got a 2011 crew cab tipper mk7 and the previous owner had removed the rear seat , when he sold it to dad , it came with the rear seat loose , maybe this has been covered , but what is the part number or name for the pillar that supports the middle belt as its not built into this triple seat and I can't find one for it , but have seen it with triple seats for sale , a spectate pillar that bolts into the seat holes to support the middle belt , any help on this would be much appreciated , sorry if its been covered before , I just don't think getting a lap belt would be road legal for a 2011 tipper , so need the part so I can fit the triple properly