My partner complained that while driving her G35X, it sounded like the spare tire was thumping in the trunk and asked me to check it out. Before I was able to take a look at it, I heard what she was talking about and I explained that it sounded like the subwoofer or amplifier was muting out and then coming back on with a large 'thud'. Sure enough, a few days later while in the car we heard the stereo mute or blank out and then again everything came back on with the thud. So, where-as initially I thought that it might be the subwoofer, now I'm thinking that it might be the stereo. Of course, this happens randomly so there is no good way to check it out. To make matters worse, it doesn't seem to last long enough to ever be able to pull over and do some sort of diagnostics.
So, I figured that I'd ask here if this is a common problem that happens all the time and someone else has already diagnosed what is needed to repair this problem?
Thanks in advance for any significant guidance in resolving this matter.
BTW: We live in NY so, it's been plenty cool / cold lately which makes me doubt that the problem is a thermal self protection issue (which would have led me to think amplifier). Also, one time I specifically used the CD player in hopes of seeing if it was just happened when we were listening to the radio (it didn't happen, but we weren't listening for that long and again it's a random problem).