Can you diagnose what this sound is? Scratching sound at higher speeds.
 

More details are listed in the description. I've tried a couple places and no one is certain.
Someone said it may be the pilot bearing or the throwout bearing. However, wouldn't that mean that it the shuddering would occur when I'm on and off the clutch only? Or what is happening to the pilot bearing here?
There is no loss of power. It drives wonderfully around town.

Does your gear shifter swing around at all? Sounds to me like some part of your drive train is loose.

does it do it in 4th gear?

Does the noise change with the clutch in?

Seems to do it on accel only. Have you done any drivetrain work lately? When did the noise start?

I vibrates, but I wouldn't consider it excess movement. It's moves around just slightly more than cars I've previously owned.

I seriously can't recall. :vash:
I know I tried it in 4th but I can't remember if it did or not.

If I push the clutch in and get off the gas pedal (going the speed I am in the video) it stops making that noise completely.

This weekend I just started it up to let it run and warm up. With the car in neutral, I revved it up to 5500. Starting at about 5000, I can hear the motor begin to make that very same noise as above, but it's more like rocks are jumping around inside.
I pulled the car up on ramps to inspect the everything underneath. Aside from all the oil residue, everything appears normal. All the heatshields are not in contact with the exhaust components.

I just bought the car (private seller). It started making this noise once I got on the highway, at that point it was too late to turn back. During the test drive, I didn't take it up to speed. That's my fault.

Does anyone know the technical term for the steering arm? The rubber boot on mine is torn in one of the seams and it's rather dry inside. I'm not sure what it's normally filled with nor what the technical term for that part is?

axle.

loose catalytic converter element?

I actually kept searching and found that it's the steering rack boot. Doesn't look too difficult to replace.

crono36, have you heard or experienced loose material/debris in the catalytic converter before?

As far as this sound goes, can I assume that the motor itself is not at fault? I drove it 2 hours home with this sound and it still starts and runs everywhere without problems/hesitations.
I'm still rather clueless. I'll definitely try to get more detail and video, but for the time being, I'm guessing it is something within the clutch assembly. I just want to be certain before I actually get a replacement clutch.

It'll sound like rattling, but coming from under the front of the car. If you get under it you can hit the cat with a rubber mallet and know for sure.