Car purchased new. At 50000 car began to self destruct, power seat, alternator, SES light, new brakes at 55K, transmission slip, engine ping. All service at dealer. At 60K SES light on again, brake calipers bad. > $4000 in repairs in 2 years. Trade in at dealer on new MSRP $40000 = $5000 before today's 2 grand. Am I still a happy customer? NO! Like the new G35, but would I buy another Infiniti? Doubt it.
I recently got this car from my dad with 168,000 miles on it, and those miles were put on aggressively; my dad has a lead foot. He traded it for an M37. There are some minor issues: oxidized headlight lenses, slightly rough transmission, a few burned out bulbs. A few months ago the radiator fell out of its rusted housing, but not the car. Besides that, there have been no major issues. The interior is still in great condition, some signs of wear on the drivers seat. Some rust issues; in the top of the wheel well and underneath the car (not noticable unless you're jacking it up) but thats my dads fault for not washing off road salt. If you take care of it, it will take care of you.
Update 9/29/16 - Terrible investment. Update 4/12/16 - I'm on my 6th set of rotors and calipers. They are JUNK! This car goes through rotors and calipers in 2 years. I'll never buy another Nissan/Infiniti Very good looking car. I purchased it new. We noticed that the car does not handle well. When you go into a turn, it feels like the front tires are beginning to slide. I purposely drove it into a corner unusually fast ( plenty of recovery space) and the car does slide badly. I took it back to the dealership and they said it was perfect. Well, if that's perfect, don't expect me to purchase another infiniti. We have replaced the brakes including calipers and rotors numerous times. Calipers freeze up often. It will stop on a dime, but having to replace the brakes every 15,000 to 20,000 miles is beyond excessive. I'll never purchase another Infiniti/Nissan.
I purchased my I30 in 2003 with 47K miles on it. It now has 195K miles on it & I expect to get at least 250K without trying. Besides replacing brakes, tires, & battery, the only major issue I've had was a transmission rebuild at 150K. The car still runs & looks like new - I still enjoy driving it today as much as I did when I bought it. I took in for service a couple of years ago & was given a 2010 G35 as a loaner car. I was expecting to be sold on trading up, but I was dissapointed in the ride & overall feel of the G35. I couldn't wait to get back into my I30. Also, the last time I put new tires on it, the serviceman couldn't believe how old it was & how good it looked.