Your search for "depowered plug kit" revealed the following:

Miata Depowered Steering Rack Plug Kit 99-05

MiataSource Depowered Steering Rack Plug Kit 99-05

Miata Depowered Steering Rack Plug Kit 90-95

MiataSource Depowered Steering Rack Plug Kit 90-95

Miata Depowered Steering Rack Plug Kit 96-97

MiataSource Depowered Steering Rack Plug Kit 96-97

DIY SERVICE Miata Depowered Pinion Welding LABOR

DIY SERVICE Miata Depowered Pinion Welding LABOR

99-05 Depowered Steering Rack

99-05 Depowered Steering Rack

99-05 Tune Up Kit

99-05 Tune Up Kit

90-97 Depowered Steering Rack

90-97 Depowered Steering Rack

99-00 EGR Delete Plug

99-00 EGR Delete Plug

SERVICE: Depowered Rack LABOR

SERVICE: Depowered Rack LABOR

NA0132850 / NA01-32-850

99-05 Steering Rack Universal Joint