这是灰色地带,两者都正确.(你说的正确:"If I were you" 比较标准.)
1) 一般过去时态 (SIMPLE PAST TENSE):I'd feel the same way if I was you = 将 "I" ( 我) 当单数,用"was" ;美式英语少用;有些人说这文法是错的; 台词没问题; 台词不是教英语学校!
2)特殊形式 (SPECIAL FORM;也称"SUBJUNCTIVE MOOD") :I'd feel the same way if I were you = 将 "you" ( 你) 当复数,用"were" .
其他例子:
(a) "If I were in that class,I'd have no time to go out."
(b)"If John were
here,he'd be so miserable."
(c) "If I were rich,I'd buy a huge mansion."
(d) "If I were to take that job,I don't think I'd be able to do my
volunteer work anymore."