Jay id found
88927-53010 for the main filter
88926-53010 for the carbon filter
I think these could be discontinued though.
What I have found is this
This is a pollen filter from a vauxhall astra f or calibra its twice the length but the width is correct and its only 2mm thicker. I just cut it down and it fits really well. I got this one from euro car parts for £1.34 got to love there discount codes some days .
Liberally sprayed with my favourite watermelon car freshener to give a hit when the purifier is switched on plus it has got rid of that horrible japanese smoke smell the old filter had!