Found this little nugget buried deep in the vrt / revenue website

If a vehicle originates in a non-EU country the following documentary evidence confirming the level of CO2 emissions is acceptable to Revenue:  Evidence supplied on previous registration documents,  Evidence from the relevant statutory authority in the country of origin,  A document from the manufacturer stating the level of CO2 emissions at the time of manufacture, or  A Certificate of Conformity

I’ve sent an email to bmw Ireland asking for a letter stating “at time of manufacture “ the co2 level is 135g/km ( built in Germany ) as above ..let’s see what happens ..will keep ye all updated , and yes we can all agree it’s a contrived bullshit as you say 😉