Just drive around with no bonnet or front bumper for maximum cold air.

By K&N air filter I'm assuming you mean panel filter, this goes in the original air box. An induction kit replaces the air box and is usually a cone shape. As Rcb says an induction kit can end up sucking in warm air, an engine needs cold dense air. A filter such as a Viper is enclosed and doesn't tend to draw in hot air.

no. if anything, buy pipercross, K&N are crap

so should i just buy a K&N air filter?

neither will do anything really.

Induction kits get heat soak so end up loosing power, although neither will be noticeable on a small engined car.

One of my mates has got a induction kit on there car, and my other mate has a got a K&N Air Filter.

Just wondering what the difference is? and which one gives more effect to your car.