I recently bought a 2010 Fit base. From everything I've read, it should have a four-speaker stereo, vs. the 6-speaker in the Sport. But I count six speakers. Are there dummy grills on the dash, or do I indeed have the 6-speaker model? And if I do, does that mean I can add USB with a simple cable instead of something more elaborate and expensive?

 

The dash ones are dummies (or more precisely, they're empties, as there's no tweeters behind them. The grills themselves are genuine grills).

 

 

https://www.crutchfield.com/learn/20...honda-fit.html

You can definitely add speakers (tweeters) there. According to Crutchfield, you may have to come up with a clever mounting solution.