Got my car back from the dealer and the result is unfortunate.
They claim the occilating bassy hum I hear from 70mph+ is from my modified oem exhaust (which it isn't since I have experienced the bass before I modified the exhaust). They claimed to takes stethoscope to the car while running. They checked the wheel bearings, as well.
The vibration I feel at the same speed interval they claim to be the tires out of round. They checked the wheels for bends as well. Again, the tires were brand new when I was experiencing the vibration (since i purchased the car 14k miles ago) and the vibration has been experienced the whole time.
09 Space Gray E90 M3 DCT: BPM (Stage 1, DCT and Servotronic) tune, Gintani Sport Exhaust, Dinan Intake