CJ..... HKS do a speed limit defender (SLR) (M3 is the code for fto mivec), AFAIK it only restores car back to its full top speed potential and does not convert from KPH to MPH, it aint cheap though €299 last year from a place in galway, didnt get it , must be cheaper ones out there ?
do camskill or funky do a similar thing