I'm looking to replace the Corolla that I've owned for the past 7
years with another small car that's economical to drive. Right now
I've narrowed it down to either the Fit, Versa, or Yaris.

I consider myself picky about car audio, and I had hoped to use the
high end aftermarket stereo I currently use in my Corolla instead of
the stock radio. It looks like that's not going to be possible though,
since it's a single DIN. The Versa and Yaris seem to have standard
double DIN openings, but from looking at photos, in the Fit the stereo
seems to be integrated into the dash. I had looked at the sport model
with the six speakers, but in the past I haven't liked the sound
quality in stock head units, even the 'upscale package' ones and
always purchased aftermarket replacements.

So my question is, are you stuck with the Fit's stock stereo forever
and ever unless you want to disconnect it and add another head unit
under the dash or something? If you're stuck with it, does it have
hookups for an amp and a pair of subs?