check out crutchfield.com
they usuakky have good prices on some really good speakers/stereos. just put in all your info about the car and they will give you perfect fitted results.
Crutchfield have some good ideas, however, make sure you shop around for prices. There are alot of other sites like Amazon.com with better prices.
2012 California Special Convertible / Ebony Black / 5.0 liter / MT-82 / GT500 Axle Backs with resonator delete / Steeda Tri-Ax shifter & base bushing / Airaid CAI / BMR LCAs / BMR Relocation Brackets / BMR Adjustable UCA & Bracket / BMR Adjustable Panhard Bar / Steeda Sport Springs / GT500 Strut Mounts / Koni STR.Ts / Shaker 500 with Infinity 6832CFs / Redline hood strut / Redline leather shifter & E-brake boots