Would hope they would have looked and checked before fitting them! But what makes you think they might be fitted wrong anyway ??
Only want to swap them cos I've not touched them since fitting in Nov 2010 / 20k miles!
....Please read my review - It's all explained there in detail. When the Twintake was first publicly launched worldwide, Forge UK used the Forge USA installation instructiuons PDF. The filter orientation, based on the moulded arrows on the cannister ends, was ambiguously open to different interpretation. I questioned it and kept on at them and a bit of an internal trans Atlantic argument ensued before it was settled. As I said earlier in this thread, it depends when Forge UK fitted yours, Lee.
As it's now well known that the front filter collects far more debris than the side filter, it's a good idea to swop them occasionally as good maintenance. < I should add this tip to my review.