I have a 2008 g37s 60k and the clutch slips bad every time I shift in high rpm and there's rattling sounds coming from under the car.
I've tried high gear lown rpm and floor it everything is normal, clutch peddle is normal as well.
Also brake light is on and vdc,slip.
I just bout this car knowing these problems for a good price also I've had vq cars before.
I'm hoping it's just the clutch and not the transmission, how would I tell if the transmission is bad?

 

Does it slip at the top of every gear or only higher gears? The rattle you describe might be normal or it might be something, can't know anything from you just telling us there's a rattle under the car. Does it sound a little like a cement truck or a diesel engine? Does it go away when you depress the clutch pedal?

 

The clutch slips only when shifting into the next gear I can hit rev limiter in 1st and be fine but when I shift into 2nd clutch slips. The rattling sound like a exhaust rattle but I know it's not I would say sound more like cement truck like you said and the sound is all the time when the car gets warmed up.