For what you are looking for, and to install yourself, I would recomend an Infinity Basslink or something like it. Will add enough low end fill for just about any music genre without "ghetto shakin" the trunklid. Its "powered', meaning that the amp is built in. Its black, wont stand out any where in the trunk. Its small enough it could be mounted directly under the rear deck, inbetween the rear 6x9's.