im thinking of doing this to my 1.2. i havent been able to find anyone with pictures of the same airbox as mine thats drilled. did you lose power when you did this? or cause any engine problems? was it standard filter?
 
At keast all the hot has somewhere to go now, sucked Straight back in to the car.

It may not be heat proof but it sucks cold air straight from a cold air source, not a hot one.

Get a stat and see what the temp is with and without the holes? Failing that buy a BMC CDA?