Currently at 53,???K miles. Had a few problems so far:
1) 2 struts blown at 45K
2) Replaced wheel bearings in the rear
3) CD changer stopped working
4) noisy valve train
5) rear axle clicking

 

Didn't you have the gas tank recall work done? They had to drop the rear suspension member, aka the sub-frame unless you're talking about something else. When they drop it all the nuts/bolts are pretty much removed from the front and rear suspension stays, the cross-members.

If you had popping before this recall then bad assembly. If after, bad service. Either way someone screwed up hands-on work vs. the design issues which I lump into the high rate of window failure, etc.

Axle click was just some numb-nuts not putting moly assembly grease on the splines, probably again a quality control issue with rear bearings failing, that's way too soon. My Z had that, so did my G.

Front dampers, you don't have to drive the car hard for that. Enough use on right type of roads, 45k is a little early, but 60k wouldn't be exceptional.

No question your experience has sucked, sorry to hear that. Just don't assume this is somehow unique to Nissan/Infiniti, and that you will do better with another marque. BMW has a load of their own problems, and fit/finish on some specific models has been among the worst I've seen (X5 body panels and drips in the clear coat is one example I've seen up close and personal).

Consumers demand more features, more power, whatever, and they expect cars to largely hold the line on price. Something has to give in that process, so more and more complexity, some useful, most not, has worked its way down into lower and lower level cars. Try buying a real compact w/o a bunch of crap on it, the stripper concept doesn't even exist, almost no one will buy them.

The root cause is the market - IMHO, people demand way too much in convenience and non-essential features at lower and lower price points, so manufacturers have responded by cutting costs on materials where possible and subcontracting assemblies to lowest bidders, look where that got Toyota with their gas pedals. People also demand a design refresh every few years in the near-luxury segment especially, also a cost that does little to address better quality in the parts that really matter. G37's have many of the same damn defects and TSB issues the 2003 MY G35 had.

 

add:

7) Trunk latch has stopped working. Neither switch nor key fob works, had to use the back seat hidden latch to get my stuff out. Already double-checked valet mode. Most likely a broken wire or bad switch on the latch, the wire bundle going into the chassis from the trunk lid is a problem area. Cost TBD.

8) Forgot to mention driver's front seat lifter RH "foot" cracked. This is what holds the front of the driver's seat down. Parts quoted by dealer $250, labor up to 4-6 hours, I picked up parts NIB OEM from another dealer $150 shipped, do it myself. There's a TSB on creaking seats but this is just broken.

9) Also forgot to add - rear wing brake light wire broken, sent the entire braking system into limp mode. $250 to find and fix. Just outside the 48k/4year warranty by 3-4 months, or would have been covered.

Now at 62k miles, time for more brake work. Rotors all around, and pads, fluid change. Just a wear item but if you drive the car hard expect only 30k-40k on a set of brakes for 2003-2004 MY with Brembos.

Pretty sure have trashed the front dampers, RH front feels like a blown seal, it's useless. So now at 63k miles, likely time to consider new damper and spring options. Tempted to just go with someone's cast-off OEM fronts until I decide what I want, and also pay for a hefty amount of brake parts very soon.

Make no mistake, even the wear items are not inexpensive on this car. No worse than its competition in the segment, I just wince when I see people picking up used early MY G's now for ~$15k who have no idea what sort of costs they're getting into, from tires to brakes, and out of warranty problems. Only thing worse I can think of would be buying a used E46 of same vintage. That has potential to be much worse, a friend spent easily $3k++ on upper end out of warranty work on a used one.