Hi Neil,
Great job!
I'd be keen to know your tips for 'correction' of the B pillar trims - mine have a couple of minor marks on them.
The piano black B pillar trim seems to be quite a ‘soft’ plastic, so very susceptible to swirl marks, even with a good, careful washing and drying technique.
I’m fortunate enough to have a dual action (DA) machine polisher, and a few minutes polishing with the DA and an appropriate combination of pad and polish removes the swirl marks. I follow this up with a couple of layers of wax or sealant for protection - applied with foam applicator and buffed off with a soft microfibre. I usually correct my B pillar trim a couple of times a year, because however careful you are washing and drying them, the swirl marks are likely to come back.
I’ve never attempted to polish mine by hand but it might be worth trying a product such as Gtechniq P1 on a hand polishing foam pad, followed up with a couple of layers of wax or sealant for protection. It’s essentially a paintwork correction polish, but should also be OK to use on the plastic B pillar trim. I’d recommend masking off the area to be polished to prevent getting polishing compound trapped between the plastic trim and adjoining rubber window seal. I’ve not used Gtechniq P1 so can’t vouch for its effectiveness at swirl removal from plastic trim by hand, but it does generally get good reviews. There are also a number of videos on YouTube - try searching on ’Gtechniq P1 by hand’.
https://www.cleanyourcar.co.uk/gtechniq-p1-nano-composite-polish