Whenever I start and stop the car, I'm hearing some sort of "feedback" from the speakers. Almost sounds like a vinyl record being scratched. And for the first time today, there's a "ding" sound coming on randomly and every few minutes. The "ding" sound is the sound the car makes when a warning light comes on, but there's no warning light. Battery gauge is showing the battery is ok. Depending on what feedback I get here, I may be setting an appointment with Eddie at Bill Luke Dodge next week. Any ideas?