May I suggest you email your question to the Daily Telegraph motoring correspondence website, honest John.co.uk ~ for a definitive expert considered answer!
No online references to K11 Micra’s with iso-fix anchor points, then “ I guess you’re shy of those anchor points ” ?
Reference; http://www.honestjohn.co.uk/askhj/
http://www.honestjohn.co.uk/carbycar/nissan/micra-k11-1992/
