check the bearings, knuckle,hub,and rotors uppercontrol arm, lower ball joints And tell me if you have engine hesitation when you wide open throttle above 60 mph to about 90mph
if you are talking about the standard radio in a lexus gs 300 which is the pioneer head unit then no its not possible your aftermarket head unit will likely have more power to deliver anyways you will lose your factory sub though so run a remote lead and rca for future use