I love my 2003 Y34 M45 ... have had it since September of 2003. Currently over 100k miles and still going strong! I want to keep this car for a long, long time.
Yes, it burns some oil - about 1/4 to 1/3 qt every 1750 miles or so in my case - my older Q45's did not use any oil! So, my Y34 engine is not considered one of the few (under 5 to 10% from what I understand) that needed to have new engines 'cause they went through more than 1qt in less than 1k miles (the requirement for replacement).
I bought the Infiniti Extended Warranty and they replaced a few parts (windshield, fuel gauge) under it. Now that I am out of warranty, I am hoping that the expensive electronics will not fail (this is true of most modern semi-luxury cars ... the parts cost a lot).
There were about 7000 to 7500 of these cars sold (more 2003 than 2004 as I recall) ... till the model was replaced by the 2006+ M35 and M45.
The design is a bit old-style, but unique and instantly recognizable on the road - which is what I still love about it. It does not resemble the "soap-dish on wheels" look that "modern" cars seem to go for ... making them non-distinguishable!
By the way, we have a car-specific forum on the Y34 and Y50 at NICO ...
Z