I'm curious on this, too.
The M104's haven't been around for that long. The
"modern" HFM-SFI M104 was first used in the U.S. on W124's in 1993.
That's only 11 years.
I'm sure there are some with over 200,000 miles or more, but you don't see that many on this forum.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".