Would appreciate advice on the following issues for my recently purchased 300SE: 1. how do I 'service' (change, clean, add fragrances to) the active carbon filter for the A/C? Previsou owner was heavy smoker. 2. the manual mentions some sort of screen that can be placed at the sun roof. Are there other options, such as adding a glass roof? 3. what are the central dash board 'non-heated' vents for? How do I use these concurrently with the A/C? 4. is there a way to defeat or adjust the automatic volume compensation for the stereo? I find it increases the volume too much for me. 5. is there a way to have the recirculatory switch always on for the A/C? 6. is there a better after market manual, for questions such as these? Thanks in advance for any thoughtful answers. Love the car!! - dan