Start with replacing the radio. That should make the most dramatic impact as far as improving the sound goes. From there start replacing other components of the audio system. The trick to this one is to get your dad involved. Maybe he'll get involved so much that he'll accept some of your ideas and you'll accept his and eventually the two of you will find a common goal and strive to reach that goal together. Plus, the whole scenario sounds like it would make for a great father and son project. His backround and your fresh new ideas sound like they could be a winning combo. Good luck