 Shares of CarMax Inc. KMX, 2.24 rose 1.9 in premarket trading Friday, after the used car retailer reported fiscal first-quarter profit that fell but topped expectations, while sales rose above forecasts, boosted by higher car prices. Net income for the quarter to May 31 dropped to 252.3 million, or 1.56 a share, from 436.8 million, or 2.63 a share, in the year-ago period. 