Jacknife has an amazing collection of tapes, vinyl, and used gear like stereos and tape decks. The quality is top notch, and if you can't find something out on the floor, chances are they'll have it in the back. If you see Trevor, tell him I sent you.
The Rose Bowl happens in Pasadena. The Flea Market is only once a month, its usually the second Sunday of the month. Its a great place to find vintage clothes, antiques and rare treasures. I once found an amazing David Hamilton book that I bought for $15 when it was worth $500.