i have to admit...... i had my car in and out of the dealer 4 times when i was having that problem, and they said the same thing your mechanic did. only 4 days later........26 miles, my clutch was $HIT!!!! disinagrated! so it was most likely the previous owner, but its kinda a heads up. so id take it to a SVT ford dealer, and have their trans tech take a look at it. they seem to be a little bit smarter ive found out in the past with my experiances! good luck.
