I have just gotten a new fiat 500 sport and want to upgrade the stereo. I have bought a kicker sub and a sony amplifier to install in the back where the spare wheel could have been.

I have been looking some hours for possibilities of getting the power from the battery into the car so I can have it wired back to the amplifier in the back, but no success. I have read posts about taking the power from the sigarette output, but the amplifier (Sony XM-ZR602) has a maximum power output of 350W (or 110W per channel) and that would be too much.

Does anyone know how to get a cable from the battery by using an existing hole?

Also is the easiest way of getting the stereo signals to connect by the hand brake in the middle of the car? I am planning to try to connect to the rear seat speakers, that way I can also adjust the volume of the subwoofer by using the fader settings of the stereo.

Any hints appreciated.

Figured it out. It is on the drivers side (Left hand drive car). About 20cm above the pedals. This is found in the engine room as a rubber "thing" you have to remove and poke a hole in the insulation. It is hard to spot and is found in the engine room between the battery and the engine.

I also found that the wireing for the back seat speakers are found on the right hand side. Here there is a connection thingie which has orange and orange + black and green + black and green wires. These are for the back seat speakers. Did not test which is which since I need a sub, but simple changing the balance on the stereo should do that trick.

Im trying to do that myself but having problems with connecting the sub to the rear speakers.
I've tried to follow ur "instructions" of what you did but have not yet succeded.

Would you mind explaining how you did when you connected the sub to the rear speakers? Would be really great.

//Tobias