There are a bunch of important factors to consider prior to buying an amplifier for a vehicle. Primarily, you must decide what the amplifier will be primarily used for. If the amplifier will be used for powering subwoofers it would be good to consider the bridged or mono capabilities as well as ohm ratings of the amplifier as well as the draw, or amount of power the amplifier will pull from the car's electrical system. The most important factor in considering an amplifier for powering subwoofers is probably output watts, which will determine the amplifier's power to the speakers and the amount of bass to be transmitted. If the amplifier is to be used to power mid or high range speakers, a multi channel (four or more) amplifier should be considered because of the ability to run multiple sets of speakers or component sets off of the different channels of the amplifier. The considerations inherent to the subwoofer amplifier are also present including watt ouput and power draw, but when selecting a multi cha