there are a few merc's with over 1 million miles on them. 300k for me to see isnt much of a shock for cars. i used to work on some high milege cars and those people sure are nutty
i had a 77 300d with over 200k and my bro had an 82 with over 500k , they are very reliable
"The current Mercedes-Benz High Mileage champ is Gregorios Sachinidis, a Greek taxi driver who holds the known record of more than 2.8 million miles in his 1976 Mercedes-Benz 240D. The latest Mercedes to be recognized for surpassing the one-million-mile mark is a 1970 280SE acquired for the Mercedes-Benz Museum Collection from its original owners, George and Luzstella Koschel of Orange County, Calif. The Koschels had bought the car new and drove it for 1,019,000 miles."