My cousin had got one off ebay here in Chicago locally that he brought back to NY. Twin turboed and I fell in love with it after a test drive. Sadly, once hurricane Sandy hit, it was totalled in the condo's garage.
Ironic.... I sold mine here in NY to some dude who came from Chicago to pick it up.
That sucks it was totalled though! Never driven a boosted one sooo...
I had a 2005 G35 fully loaded, picked it up with 55xxx miles. Nav, aero pkg, premium pkg, etc, and all stock except for a few minor styling mods. At first I LOVED the thing. It ran perfect, at the time too. Picked the car up from a guy on a local forum, so we took it to the mechanic to have it diagnosed before I picked it up. Mechanically solid. The sound of the stock exhaust even today is one of my favorite sounding ones ever.
Then the problems started.
A few months into driving it, I got a feeling that the car was made to look good, and nothing else. The interior felt cheap despite the fancy clock and heated seats. The navigation was beyond useless unless I wanted to pay $100+ yearly to have it updated by the stealership. So in short, I had an out-of-date system that got me completely lost a few times. The interior lighting could have been better, too. I could tell something wasn't right when shifting... shifted fine but made unpleasant noises. Brought it to a shop.. dime sized hole in the transmission housing. I had a warranty that I spent 1100 extra on as it literally covered everything except for damage to a few select things. Warranty f**ker comes to look at the car, denies the claim. Why? He cites "neglect" to the car. The reason? The tires were bald. The tires were 5 years old (from before the owner before me I guess). I knew they were getting there as they tech warned me when I got it inspected initially. I bitched and moaned, as the car was certainly not neglected upon, at least when I owned it. They sent another asshat to look at the car, but he determined the car was not neglected, the warranty goes though, and I get my new transmission.
Then, driving to work one day, my door actuator took a crap. Couldn't get it up (that's not what he said). Got that fixed.
Then the front left caliper took a crap. Then I curbed a wheel and got pissed at myself
I had a CEL for a week or so at some point. Never looked at it as I didn't notice any issues with the car (for once). CEL randomly went away after that week.
Air bag light kept coming on. I just did some weird key trick to reset it each time
Also, tire pressure sensor light would come on every time I went for a drive more than 30 minutes or so. Sensors checked out to be fine, issue was diagnosed as pressure change due to tires heating up. But it came on every time I took a long drive, so I just ended up ignoring that, too.
Summary - The car felt cheap after owning it for a few months. I replaced every damn part in my Honda and never had as many issues as I did with the G35. It left me with a bad impression for a car generalized as "upscale, near luxury".. It didn't even feel near it. Sold it after owning it for about a year, for my RSX and haven't looked back.