Kenwood Excelon KFC-X463C Excelon Series 4"x6" 2-way car speakers at Crutchfield
Infinity KAPPA463XF 4" x 6" (104mm x 157mm) Two-way Car Speaker - Creative Audio
Bio 4x6" 160 Watt 2-Way Car Speaker Set - CT Sounds – CT SOUNDS
Amazon.com: Pyle 4'' x 6'' Three Way Sound Speaker System - Pro Mid Range Triaxial Loud Audio 240 Watt per Pair w/ 4 Ohm Impedance and 3/4'' Piezo Tweeter for Car Component