Help Plzzzzzzzzz................

I Want To Get Some 20'rims For My 94 Es300 But I Dont Know If It Will Fit Or If I Have To Do Any Modz To Make Them Fit......does Anybody Know Some Type Of Info.the Rim Shop Told My Friend That The Biggest He Could Go On A Acura Legend Coupe Was 18' But He Got 20' Rims To Fit With No Modzzzzz..............if Anyone Has Some Info It Will Be Appreciated Very Much Thanks Fellazzz And Ladies.........