What does the cryptic crossword clue "US car notably breaking the law (12)" mean?

The definition is "law". The wordplay uses an anagram. anagram of US + CAR + NOTABLY = CONSTABULARY; definition: "law" The answer is Constabulary.

US car notably breaking the law (12)

Telegraph Prize Cryptic #3095 | 17 Across | 2021-02-14 flower