I am the proud owner of a pre-owned cream puff. From the information I can find I thought the rear end has a limited slip or torque sensing unit. This car will spin one wheel until the cows come home. Thoughts or info? How do I tell if iI have it or how to repair or replace it?

replace it http://www.miata.net/cgi-bin/isc/classifieds.cgi?action=show&CategoryID=114&SubID=1090&Variable=generic.variables&Session=41be9d2d59058403