Adding an amp to an amplified or premium factory system
Old School Stereo: Old School Monster Car Audio Amplifiers
Best 5-Channel Car Amplifiers Maximize Your Car Audio - ElectronicsHub
Car Amplifiers: Car Amps - Best Buy
2 Channel Car Stereo Amplifier - 400W Dual Channel High Power Audio Sound Auto Small Speaker Amp with LED Light and Remote Control, Support SD/USB/MP3/FM/Radio - Walmart.com