Hi A900
Take a look at
www.roofbox.co.uk They are based not far from me and offer many bootliner options as well as roof bars, boxes and other items. The bootliners in particular are good in that different sizes of rim are offered on the bootliners they sell. Useful that, if you carry anything quite wet or muddy. Oh, and they happily send items by mail order.
And for car mats I can recommend
www.SimplyCarMats.co.uk I bought a set of 4mm thick rubber mats for my VW Golf. They fitted perfectly and even utilised the round clips on the carpet, so they don't slide around. They also offer carpet mats in various thicknesses and colours, and some of these can be customised if that's your thing.....
Lots of rear bumper protectors on Amazon/Ebay, but I don't have one of these so can't comment further.