there was a guy on here that did a sick build with 15's in a bandpass box ported into the passenger compartment. that was an absolutely gorgeous install. Unless you do something like that in the marquis like i have or a vic, you are fighting an uphill battle with the gas tank between the trunk and passenger compartment. Mine sounds ok sub back, port back. There are many days I wish i had an suv or a normal car with a straight trunk then passenger compartment.