If you're in need of an amplifier that takes up little space but delivers a big sound, Soundstream's Stealth amplifiers can fill the bill. At about 3" deep by 7-1/2" wide, the ST4.1000D 4-channel amp will fit just about anywhere, delivering 90 watts per channel to your front and rear speakers, or up to 250 watts per channel in 2-channel mode to your subs. That's a lot of power in a tiny package.