Currently have some Autoglym stuff that ive had years and is pritty rubbish proberly why i still have it a few years on i use it on my diffusser here and there. Just wondering what you use? i was looking at this
https://www.cleanyourcar.co.uk/wheels-and-tyres/chemical-guys-new-look-trim-gel/prod_143.html
https://www.cleanyourcar.co.uk/wheels-and-tyres/chemical-guys-new-look-trim-gel/prod_143.html