If it’s the standard matt colour Cup trim (not painted) then Autoglym Bumper Care gel produces a very nice deep/wet look and also beads very nicely. Its about £5 from Halfords.
Best to clean the trim first with some APC (all-purpose cleaner) and a soft bristled brush, removing any stubborn tar spots with some Autoglym Intensive Tar Remover, then apply two coats of the gel with an old microfibre cloth, rubbing it in well and buffing off with a clean microfibre after each coat.
It removes easily from the paintwork and two coats should last you at least a month, then all you need to do is top it up as and when needed.
Just got in from doing mine coincidentally…how sad am I at this time of night!? Oh and that’s a rhetorical question, I don’t want any answers thank you!