Thanks for the replies. I have located an independent who works on MB's and has both the knowledge and right attitude. He does use MB approved parts but he doesn't charge the dealership price. I could not use a dealer anyway - they are over 150 miles away from my city.
Mobil 1 has been a staple in all my V8 Corvettes (the 96 had a warranty provision that to use anything BUT Mobil 1 would void the warranty - but I guessed that was a GM - Mobil $$ thing). Anyway, I was reading that the Europeans think we Americans are nuts for abiding by the 3000 mile myth of oil changes. I tend to agree and find most manufacturers are now relaxing to 5K (My new Jeep GC - lets you decide and program the computer at 3, 5, or 7,500 intervals for maintenance reminders).
Thanks again for the welcome and answer to my questions - I'll check out the oil posts.