I have a Meta immobiliser on my mx5 mk1. I'd like

disconnect the battery both leads then join them together and leave for half hour or one coffee in the local bar and a ciggy then reconnect and it should start ,this mazda uses the same software as a ford mondeo and a jaguar S type of the same year and it works on them

Is the key fob battery flat? If so fit new CR2032 and re-sync to car by pressing lock 4 times in succession

This should help you??

4.2 Pints for a 1997 Mazda Miata, but that's for the U.S. MX6, I believe.

It's immobilized (won't let you start the engine) or won't immobilize now?
If locke your engine then try turn key on, press start to do a short crank, let go for 3 times cycle then on 4th let it start as normal.
Have you checked your meta M357 Alarm user manual for owner unlock sequence?

worn bushings,worn shocks, worn wheel bearings loose wheel nuts,loose suspension components are just some of what may cause the rear shoddering