The rear wiper blade has split so as I was in town I popped into Halfrauds and asked a staff member which blades they do for the RRS and bought the Bosch H403. This does fit the arm, and is the correct size, but during it's sweep, it fouls the spoiler. I compared it to the Trico T400? I took off and the Bosch sits noticeably higher, hence the fouling.
I have had a search and the Bosch seems to have been used successfully by members on here. The genuine LR blades are ridiculously expensive for what they are at just short of £40 from the stealers.
Has anyone else had the fouling with their Bosch blades, and can they be adjusted (I think I will take it back to Halfords so don't want to butcher it unnecessarily).
Another option is the Trico EF400 as listed on their site.

Hi, I had the same problem, when I bought the car last year it knocked as it went over the centre, at first I thought it might have been the mechanical linkage, it was only when I had a light bulb moment and saw the bright spot on the end of the wiper arm I realised it was catching the spoiler, I just grabbed the blade while it was still in the arm and gently reformed it (bent it) by squeezing it along its length, works great now.

Thanks RugHead, I was wondering if something like that might work. I will give it a go
As a stop gap, I fished the old blade out of the bin and superglued the spilt, Not ideal but if the "remoulding" doesn't work it buys me a few days. The problem I have with returning the Halfords one is that I put the box in the recycle bin and that's been emptied.
If all else fails, I will get one of these;
https://www.advancedfactors.co.uk/dkb50068...8134-p.asp

Fair play to the staff at Halfords, I took it back, they agreed it wasn't right, put one of their universal 400mm blades on the car and despite me having "recycled" the box they gave me £4 back.
I've bookmarked the AF Trico blade for the future.