VERY Weird 'Noise' From The 300 CD
 

Got the new starter in my CD. This morn I drove to the post office.
It made a very weird noise, starting at about 5-10 mph, a whooping sound> woop woop woop wooping, faster as I accelerated. At 40 45 mph was SO loud I expected others on the road to notice, but no. Opened windows, no sound from outside.
I reached up & put back of my fingers on insturment panel, my fingers literally were bouncing off the inst panel. Got home 'bout an hour ago, will remove panel tomorrow & see what I can see, hopefully something simple.
Anyone else have similar issues??

Speedometer cable? Would change speed while accelerating and is in contact with the instrument cluster.

X2 ^^^ .... Don't drive it a lot, it may harm the speedo gear in the transmission from the extra friction/resistance.

Can the actual cable itself be replaced, or must the whole assembly be replaced, end to end?

The cable can be replaced if the housing/casing is in ok condition. If the cable looks ok they can often be thoroughly cleaned, the casing flushed with a solvent and the cable sparingly lubed with lithium grease. Lube the upper foot of the cable very sparingly to prevent the grease from getting into the speedometer head.

I'd disconnect the cable and see if the noise goes away before doing anything else...

Good advice X2^^^