Wanted Waterproof covers for rear bench seat - MY23 Ocean

[KevH]

I am looking for waterproof covers to attach to the two-person back seat/bed when we are camping, cooking or carrying the grand kids.
I have the Inka style in mind, preferably black to match the front.
Unfortunately Inka won't sell me a two-person rear bench cover unless I buy the full front and rear set, or want one for three people, which I find a bit odd but I'm stuck with.
If anybody has one they no longer use, please PM me.