Pain in the *** Newbie Q's

Looked at a year old S4 on friday, wondered if anyone can answer some questions,

Is the S4 bodykit exactly the same as the S-Line A4

What's the deal with the Memory CArds in the Sat Nav, can i drag and drop MP3's onto them, and will the unit display the names,

Has anybody put genuine RS4 wheels on a S4 yet,

What are the options if it dosen't have factory Bluetooth?

I know it's painful but would really appreciate any help, lastly,

Has any one on here moved to an S4 from an M3, and should I consider an RS6 at around the same budget £30K?

Thanks again.

Appreciate the thoughts guys, after serious consideration I collected my B6 S4 yesterday, it's an Avant in Nogaro Blue with Black Leather, I decided to go for an older and cheaper alternative. Presumably I am now forbidden to post here again as my car is to old.