I know a buddy that has a S4 with bad acid etching from the chemicals they use in winter and we did a buffer with rubbing compound and a cutting pad and it helped alot. It just depends on the sevarity u may be able to get it with a polish but most likely youll have to work with a rubbing compound and then work down to a fine polish and then use a good wax to keep it from happening again.
Got pics?
"Do you guys put the key in "balls down", or up?" -BobbyT 10:28:19 03/06/09