My ride is a Mercedes SLK R171 model , the underseat have some Electronics somekind like ECU  under the driver side and a HarmanKardon processor under the passenger side which come standard with the car , so there is no place for me to stuck the active woofer under there , on the rear trunk because of the convertible design there is no place for the wires to go around and the sound proofing will make the bass not reaching cabin , so the only way was to install 2 of these active subwoofer behind the driver and passenger seat ...

the harmankardon audio is quite satisfying already, it had the bass punch but just cant provide a low down vibration that a normal woofer in a box produce 

as the enclosure is quite shallow the thing i worried is the bass wont go low ...

i never tried before so need opinion from all expert sifus at here ... 

And thanks for giving advice , really appreciate it