Organization that promotes flossing and good oral hygiene: Abbr.

Transport you'd hail in a city3 "___-ching!" (cash register sound)3 German car brand with a four-ring logo4 ___ Grylls who stars in "Man vs. Wild"4 Got off ___-free (without any punishment)4 Take something in one's ___ (deal with a difficult problem calmly)6 ___ Bing, Matthew Perry's character on "Friends" intended for a supporting role before becoming central to the series8 Grain in a granola bar3