L994 toyota camry radio amp

Mechanic told me that the radio amp was burned out (apparently under the shotgun seat) which was what was shorting out several fuses and causing several other lights not to work.

This diagnosis was followed by my discovery of a chewed up bag of chips in my trunk. Mouse perhaps the troublemaker?

Where should I proceed to go to fix my problem? Do you think the radio is toast now? Just the amp? Wire that could be repaired?

Thank you for your time.