The side to side movement of the engine also moves the gearbox. So it will help those missed gears in competition and track days as well as in normal daily use.
If you have an aftermarket stainless steel exhaust manifold, it will help you too. Any reduction in movement and vibration will reduce the likelyhood of cracks in your manifold.
It is currently available for the MK1 MX5 1.6 only - 1989 to 1998 and we are working on a suitable version for the Mk1 1.8, Mk2 and Mk2.5 - more later.