VERY GOOD ADVICE, tridgirl!
I am a USC alum (as most of you know) and oddly, I didn't feel TOO much pressure on the clothes money thing--but I went to a private prep school for high school, so perhaps I didn't notice it because I grew up with it--I've always been a serious clotheshorse anyway, so that's never been a problem, and I drove what was considered one of the 'right" cars--a VW Jetta. LOL
Academics at USC are VERY competitive, more so every year that passes.
I would suggest calling SCs admissions office and telling them about your grades and then regardless of whether they need them or not--SEND THEM, it can't hurt. I applied early decision (back in the days when they still had that!) so my fall grades weren't factored in, but for regular decision, if memory serves, they were.
Good Luck Car-- I so want to be able to welcome you to the Trojan family--you've got the spirit and drive to be a part of it!!!
Go Trojans!
Amy