My machanic tells me that 328 (96) at 100K miles is just breaking the engine and it's at peak performance. And it should last for a long time if maintained good with regular service.
From his experience (synthatic oil and regular maintenance, ie belts, radiator fluids, valve cover gasket etc) he has put 350Kmiles on his old BMW 325 and still going strong. He has painted the car and also done some rust-proofing.
350K miles on the car is pretty impressive number.
What do you think?