The passenger footwear fuse box (RHD) is helpful separated in to live and switched fuse banks. There are loads of switched live options free but from my experience, the hardwire kit I got from NextBase had a 'large' piggy back fuse kit. The switched live fuse bank are all 'small' fuses. I chatted up my local Halfords person person and got the small fuse adapter which works perfectly.
As above, I've previously had a problem with the rear camera affecting the DAB signal so I ran the cables through the handles on the headlining as a test for a few days. Didn't seem to have much effect so I've now got the cable in through the A/B pillars ready to take the boot lining out and fit to the rear window properly.