triple: Without delving into the entire project, I am looking to power a car stereo (and possibly a small DC motor).
Maybe I'm being old fashioned, but it was usually preferable to use linear supplies, as opposed to switchers, in audio applications. Ripple voltages and possible radiated noise from the switcher can have nasty effects in your audio path. (Like high freq. buzz). And you are probably really wanting a 13.5 VDC for your car stereo to get the most out of your final. It is probably wise to take your motor drive off of your input filter network via a separate path so that your amplifier supply and motor supply are isolated.
Joe
