where do you run the power and signal cables for a sound system in a peugeot 307
Run the power cable under the carpet on the side of the car with the battery and the signal cables under the carpet on the opposite side so that they don't catch any interference from one another. If you don;t know how to do it properly you may want to pay someone else to do it or try searching online for a guide on what exactly to do.
well for convenience, id run the power cables on the side of the car that the battery is on and the rca's on the other side.