"I purchased this vehicle new in 2003 and have driven it over 41,000 miles. Problems so far have been one sensor (didn't affect driving at all) and the rear window shade motor has failed twice. Both problems were corrected on warranty at no charge to me.
Pros: Plenty of power, excellent stereo, excellent handling, nice ride except on bumpy roads, and very supportive driver's seat. Infiniti is the first car I have owned where I can drive all day and not get a backache. Infiniti has one of the best navigation systems available both feature-wise and ease of use. My 03 Infiniti navigation system has features NOT available on my brothers 06 Mecedes S Class.
Cons: After over 4 years of driving my I35, I am still looking for the cons but thus far, haven't found any.
I considered getting a new M35, but just can't bring myself to part with the I35. Instead, I purchased the Infiniti Elite 4-year extended warranty with zero deductible. I shopped and wound up buying it from an out-of-town dealer and saved hundreds of dollars. Don't be fooled. The Infiniti Elite plan covers much more than 3rd party warranties, and actually costs less. Dealers set their own price for the extended warranty, so shop around. The Infiniti Elite plan even covers the stereo and navigation system."