SAN FRANCISCO -- Ford Motor Co.'s surprising profit drop and subsequent stock retreat on Friday led the broader auto sector deep into the red with the rest of the equity market. At last check, Ford was down almost 12% to $16.58, while rival General Motors Co. saw its stock lose 5.3% to $36.63. Toyota Motor Corp. and Honda Motor Co. shed more than 2% each. The auto parts group also took a hit, with American Axle & Manufacturing down 8%, Magna International off 6% and both Johnson Controls and BorgWarner down more than 3%.

Copyright © 2011 MarketWatch, Inc.