Whilst looking into rubber floor mats for my 2015 Doblo I came across Gledring. Not a name I recognised but they produce nice thick mats with a lip which keeps in liquids. RRP is meant to be £41.75 and Amazon sell their range for £36.99. CarParts4Less currently have them for £28.45 with free delivery.

I've received them and can confirm that they are nice and thick and have a pleasant vanilla smell!

https://www.carparts4less.co.uk/cp4l/p/-/-/-/-/?947587338&0&

I didn't manage to find any voucher codes which can be used with accessories.

What PSA vehicle are they designed for..?

They're for the Doblo 2010 upwards. They're these:
https://www.driveden.com/car-mats-boot-liners-c387/tailored-car-mats-c28/fiat-doblo-mpv-ii-2010-2019-tailored-rubber-4-piece-mat-set-p97044