For audio, I recommend either Autowerks in Northbrook or Audio Driven in Oak Forest. They are excellent shops that do top notch work for which I have personal experience with both. Autowerks would also be able to help you with replacing the rear spoiler as they are a full service body shop. I would recommend sourcing a fiberglass replacement from either KurumaZ or Powertrix if you want to retain the OEM style.