Hey all,
I came up on a ten inch sub and an amp. I really want to put it in the fit but I don't know if I would need a new deck to put in the sound system. Anyone have upgraded speakers in their fit? Advice?

 

You can use a line level adapter (sometimes called a hi/low level adapter) to do add a subwoofer without upgrading your stock stereo. Basically all you do is tap into the +/- speaker wires, run them to the adapter,then run your RCA cables from your amp into it. Power the amp as usual.
Any car stereo place worth a lick should have them.

 

like above states, a converter that changes speaker signal to RCA will work. your hardest part of the job is removing the bottom bolt/screw of the radio anchor. its above the right cupholder, slightly tilted towards rear of car. I removed my center console to get to it, its a pain.

entire interior of this car is easy to remove and flexable. I just got done installing all my wiring for a 4 channel amp and subwoofer setup. power down the driver (left) side, all the RCA's, remote wire, and some zipties to keep it tidy down the right passenger side