** Shares of used-car retailer CarMax KMX.N fall 6.9% to $74.5 premarket
** Co reports Q4 profit of 58 cents/share, missing analysts' average estimate of 65 cents/share - data compiled by LSEG
** Co posts Q4 revenue of $6 billion vs estimates of $5.96 billion
** Decline comes as U.S. President Donald Trump's tariffs on automotive imports raise concerns about affordability of new vehicles
** As of last close, KMX stock down 2.1% YTD
(Reporting by Padmanabhan Ananthan)
((Padmanabhan.Ananthan@thomsonreuters.com))