Luis Alvarez/DigitalVision via Getty Images Asbury Automotive Group (NYSE:ABG) has been a mixed performer over the past year, up just 10% and below last summer's highs. In September, I rated shares of ABG a "strong buy," but their performance since then has been disappointing. The stock is essentially flat, while the S&P 500 has risen by 16%. Given this underperformance, it is time to revisit to see if the underperformance is merited or if the opportunity for 15+% returns remains. I remain bullish. Seeking ...