idle farts?

[dbraun37x]

I noticed on my G37x 2010, I am experiencing idle "farts"m basically I'm watching my idle meter go up and down. I haven't stalled (as of yet). I brought to the dealer, and of course they couldnt find anything...
2nd topic: Has anyone ever had a smell coming through the vents, smells like a melted plastic bag and or burning oil...
3rd: Does the engine normally have a hard knocking noise after a long period of driving?
I know I am new here, but since the the dealer hasn't noticed anything after 3 visits... perhaps someone with the same problem(s) could shed some light.

PS: I love my car, don't get me wrong.

D'

[Amays U G37S]

The plastic burning smell, is well, normal. No one REALLY knows the cause. Might be something with the In-Cabin Filter. I unno. Everyone says the same thing about it.

The motor should never knock. You need to put in the highest gas available or anything over 87 octane.

When the car is first turned on, the idle may jump a little, but it should be between 500-800rpms when sitting idle, with that sweet sweet exhaust tone.

[dbraun37x]

thats the thing though... I keep on putting in between 91 and 94 oct. It just doesnt make any sense to me either.
Second... should I even bother with an air injection kit? Do you notice that there is some rattling in the car too? Sounds like I got a Lemon!
D'