Bosch +4s were known to be questionable in the BMW world for the different 3 series I have owned.

I just drove 50k on the B-P in my ML and had no worries. So I stuck with them. Next 50k I will go back to OE standard plugs.

But I am not re-doing that job unless I have to. Too much work for a problem I don't have.

Dickie

00 ML320
96 325i