BMW is recalling all E46 M3s built before March 2003, essentially for an engine rebuild where they are replacing the con-rod bearing shells, which may fail.
The official reason is that they have failed BMW's quality assurance test - quite why it's taken this long to discover it is a mystery.
This will mean returning your car to the dealer and on return you will have to run in the car once more.
There is no compensation and BMW is trying to keep it very quiet. Official recall reference is 0011940100.
Alas, I don't own an M3, e30, e36 or e46! just a humble 318i

But, I do have a friend with one!

he rang me to tell me of this earlier, he expects to get it back by next Monday / Tuesday.
Tonight, we've been buzzin about in his 330D Loan car, wow! I'd say the diesel is almost as much fun as the M3 ,having driven both , unbelievable torque its power delivery is so so smooth.
I really need to re-consider my views of car diesel engines!
8)