I am no audiophile (anymore) but are you sure you want a class D amp for your interior speakers?
Usually you want something like Class A (best quality-least efficient) Class B, or Class A/B (best bang for buck). Class D is the worst quality (but most efficient). Class D's are great for sub amps because you want tons of power (the great efficiency), and your only reproducing a limited bandwidth 20Hz-80/120 Hz, so your THD doesn't really matter (Total Harmonic Distortion)