It's true.
The Driveshaft Specialist will sell you a new Miata driveshaft for $300. It's heavier duty and comes with greasable, REPLACEABLE U-joints. Almost next-day service. No complaints.
http://www.driveshaftspecialist.com/...tml/Mazda.html
Other alternative is used. I have a two 1.6 and one 1.8 driveshaft sitting in the garage. They all have a "notch" you can feel when you turn the U-joints, but were not vibrating when removed. I just didn't like that notch. You could make me an offer.![]()