I wonder if they were different for 2002? There's a set on ebay marked up as 98-01 and they appear to have caps too. But both my 2002 '8s don't have caps and there's nowhere a cap would fit. They have a 'polo' shaped plastic piece around the hole in the carpet which clicks into place with the stud on the floor. When in postion, the stud is flush with the 'polo'.
Photo to follow - how sad are we?