Thanks for all the help guys.
I picked up from JUSTJAP one of these as i was near by.
I also grabbed off a mate a set of cheapy Auto Gauge Gauges, Oil Temp and Pressure just for a test fitting.
The hole on the Shadow Sandwhich adaptor is not the correct thread for the sensors with the gauges.
They go in about 3 turns then come to a halt.
The AUTOGAUGE sensors have a sticker on them saying 1/8-27NPT, which i assume NPT thread which is 27threads per inch.
Would this mean that the Adaptor plate is 1/8BSP?
JUTSJAP assured me that AUTOGAUGE would screw straight in.
It seems that most aftermarket gauges use 1/8NPT. I will give MANIA a call in the morning to ask about there DEPO gauges, and what thread they are.
Because they are Japanese maybe they use the 1/8BSP which i believe is the stock thread on the MX5?? Please correct me if i am wrong.
One other question, if i get an adaptor, would that not affect the pressure/temp readings as the sensor would not go all the way into the direct stream of oil would it??
Thanks so much for everyones help so far.