Car selling platform Carvana Co CVNA.N hopped 13.1% higher following Piper Sandler's upgrade of the stock to "overweight." By Stephen Culp NEW YORK, Sept 12 (Reuters) - Wall Street advanced to two-week highs on Monday with few impediments to thwart a three-day winning streak as investors awaited crucial inflation data. The Labor Department's consumer price index (CPI), expected before Tuesday's opening bell, is this week's main event, and will be scrutinized for any clues regarding the length and severity of the Federal Reserve's policy tightening phase.