if its an auto you could also bump up the line pressure slightly to give quicker shifts
make a better CAI, a heatgun and pvc pipe can be used...
advance timing for 98ron fuel, dunno what the gist of the procedure is but there could possibly be a connector that needs bridging...dunno though, or you might be able to trick the AIT sensor to advance timing. then again i dont know if the focus
ecu will also adjust air/fuel ratios.
Make up a jaycar digital fuel adjuster, as long as the MAP/
MAF sensor gives out a voltage signal youll be alright. If it is frequency-based- like all (ea-ba) 6 cyls then it wont work.
The above jaycar kit would most likely give excellent gains if setup on a dyno.