The question is which radio you prefer. With the leather comfort package, only the RCD 500 could be combined as the cheapest solution. For 350 euros more was the small Navi RNS 300. On a CD changer, which the RCD 500 has, I put no value on. But on the sound and the ease of use. Is the RNS 300 a new development? How is the sound of the two systems different? Greeting deBORA