drivage nen ford ka, front 13cm caps(car audio proffesionals) installed, in the case room 25cm bandpass housing over a 4 channel end stage fired. the 13s in the front doors but the lower middle area are not really implemented. the bandpass is clearly only responsible for bass. QUESTION: someone has already built a reasonable rear shelf for the Ka. the original shelf is, my guess, namely totally angled, and much too thin around reasonable membrane the lower middle gu MfG, lukas.