MA Driver stopped by police following citizen cell phone report of erratic operation.  Police confirm minor lane control issues before stop on busy highway.  Driver admits to drinking wine at party, but claims she is designated driver.  Police allege driver failed standard field sobriety tests.  Defense prepared to argue location of testing in breakdown lane was excessively loud, cold and close to traffic, and any difficulty with testing was due to nervousness, fear and embarrassment of situation. DWI charge dismissed prior to trial.