I'm considering putting in new speakers, a sound processor, amps and subwoofers. I wanted to ask anyone who has already done this if they've run into power problems, considering how small the battery is, and if its necessary to put in a bigger battery and altenator?

 

No bigger alternators exist for the Fit, and bigger batteries can only be used if mounted in the cabin with remote cables. Use the "search" button to find multiple threads on your subject.