Tad late on the reply, you can get an induction kit for a MK1, pipercross do one, its a complete replacement part that fits under the metering head and is an aluminium cradle thats full of foam has a larger surface area and you do a way with the pipes leading to it.
Performance wise there was no difference compared to the K&N filter i had fitted, apart from a raspy noise if you reached the higher revs.
bought one of ebay for ?35 they apparantly sell for double this, certainly not worth the price.