I have a 2003 350z track which ive owned since new, serviced at nissan dealerships up until the 10K service and at MTA approved garages since then for the 20k and 30k services. My car now has 31000km and i have used shell helix ultra oil 5w-40.
My engine is now making a really loud noise and after having it towed to a Bankstown Nissan. it has been sitting there at their mercy since the 2nd of December.
Initially diagnosed with case hardening in the gearbox i had it replaced under warranty, to fix the so called noise. Apparantly my clutch and flywheel need changing, according to nissan and they want me to pay 3500 for the both.
The engine knock was still there, fifty days and counting my car is still there! Nissan dropped the sump emptied the 1000km used oil and disgarded it. They then realised they wanted an oil sample and took it out of the filter, a filter whose job is to filter contaminants. They claim that the engine oil was "not specified" and hence will not cover the engine under warranty, a quote to get the whole job done is $$$20500. HELP!!!

 

There ya go, this is the right section. It happens pretty often, don't worry about it. (the posting 350z problems under "Feedback and suggestions" for the my350z.com site)