Thanks Bill, there certainly seems to be plenty of choice!In the boot, I just use the net that came with the car. I got some basic mats from here:
Over 18,000 5 Star Reviews. Manufactured in the UK. Free delivery on orders over £40. Fully tailored carpet and rubber car mats. Water-resistant and anti-slip. Personalised car mats available now!carmats.co.uk
They seem like decent quality and they fit well but I've only done about 10 miles since I put them in so I can't comment on their durability yet.