99 miata need some help.
 

looking into maby getting a ms unit for my miata but they only sell them for 90-97. what has to b done to make it work with mine. am i better off finding one already built for my year and if i did that how easily would it swap into mine? also if i put one in my car will i b able to pass emissions?

We only sell an MSPNP for the '90-'97, but there's several people who build their own adapter harness type or similar setups.

MegaSquirt is not emissions compliant.

If the main reason you want a Megasquirt is cost, then you can build a basic unit yourself and be done with it. It will run the engine, but you will save yourself a lot of grief by buying it already assembled, tested and with a basemap preinstalled for your car.