I read all the IMS posts I could find before I bought my 2002 4 summers ago with 45k miles. I knew the chances of failure were small, but the concern was always somewhere in the back of my mind. My car has about 90k miles now and I don't expect to need a clutch anytime soon, so I didn't expect to have the opportunity to replace the bearing with most of the labor already covered by the clutch job. I have also read about some very high mileage cars with the original bearing, so I couldn't quite justify the $2-3000 expense of IMSB replacement.
I followed the IMSG posts on a few forums with interest, then signed up early and paid $365. I think of it as a magnetic oil plug that is being continuously monitored, and it cost a lot less than other mods I have done in the last few years (Litronics and an AerokitII will not warn me of engine failure). I hope it will also give me some added peace of mind as I read any IMS failure posts that may come up. I installed the sensor when I did the year end oil change, and I will finish up the wiring before the snow melts in Minnesota.
Similar to a warranty or insurance, I viewed this as a cost/benefit decision. I am sure everybody has different and valid views, but I decided it was worth it for me. Now I hope I never need it!
