HA!!! THe S2000 has some MIATA basings? ? ? ? KILLER! I wanted an S2000, but they were too pricey to interest me. I bought a used Miata for $4900 and enjoy THE CRAP out of it. hahahahhaha I LOVE hearing the S2000 has Miate parts or Miata based parts. that's great!
Look at it like this, Our chains aren't made by Suzuki, and you'll find the same chain on a Honda, or a Yamaha... Same with our fuel injectors, etc... So, an LSD made by Quaife goes into both the Miata and the S2000... Doesn't really mean anything.
Been on several long drives with folks in their S2000s and they are great cars, will be a task to find a gently used one, and I certainly wouldn't spend .2 cents on anything off of FleaBay, but I'd own an S2000 alleged dif issues or no, all the owners I've met smile a lot.