i have heard bad things up the pipercross viper and the downside of the bmc is that they dont make one for the
ibiza. You have the icv goin to the filter and the maf sensor so u will need to make holes for these some how.
But where I saaid i've heard bad things about viper, I have a pipercross vector open induction kit, which people on her dont rate and wiv a nice big air feed I have no problems with it! Give it a good clean every other month and no problems.
But again most people dont rate a open induction kit and rather a panel filter and drill holes in the oem box. I've done this to and noticed no differance compared to my vector filter, i'm sure one of the mk3 did a log wiv his green cotten dynotwist closed filter and then removed the box and logged again. Found out he draws more air in when the box is off and the same temps.