my method is to clean real well with a degreaser diluuted 10:1. then use something like poorboys trim restorer. thats actually the only product ive seent o actually bring something back rather than just dress it up.
If you are talking about that grainy trim on cars the Poorboys trim restore is about as good as it gets. I've also read the 303 is also a good one have not used that one myself but lots here swear by it.
I was just going to start another thread for this. I tried AIO on trim but it doesnt really revive my trim. My cars not old its a 2000 and its perfectly cared for. 303 is just a cover up im going to have to get some poorboys trim restorer.