I was a bit confused by that part of the article. It mentioned "Rolex watches and expensive cars" as examples of the things bought to launder the money. But bot

I was a bit confused by that part of the article. It mentioned "Rolex watches and expensive cars" as examples of the things bought to launder the money. But both of those have unique identifiers (rolex S/N, car VIN) which in both cases is recorded on sale. Surely that makes them terrible ways to launder money? Am I missing something?