Thanks for the feedback, ft_sjo!
I've always heard that distortion in automobiles, the threshold for audibility is 1% on music and 0.1% on tones.
http://www.bcae1.com/thd.htm
The worst amp is spec'd at < 0.05% (measured at 1000 Hz usually). Most of their stuff stays south of 0.1% at rated, throughout the spectrum, so it shouldn't color the sound in any meaningful way. Even then, the first even harmonic is the dominant one.
http://www.41hz.com/forums/content.p...b-measurements
Cars are pretty squeaky and rattley, so I'll take my chances. Laziness is really the obstacle here.