It may be that because the transaction is completed via a UK site and VAT is applied, any import duty is sorted by the seller, don't know.
I noticed when tracking my order, the items were held at customs for days saying "awaiting customs clearance" or similar.
They have got a lot of very bad reviews but apart from the delays all my parts arrived in perfect condition, well packaged and with no errors. They have a massive choice; I think they stock 15 different air filters for the N20 alone, and prices are excellent.