I can get anyone a gallon of Motul air filter cleaner. Pour some in a bason and steep your air filter in it, it'll take all the dirt from the filter. You'd be amazed at the dirt that come out of it.
Can also get air filter oil. and Motul fuel system cleaner too
I've cleaned K7N panel filters twice. Main things to watch out for is to make sure they are totally dry before spraying them with the oil. Also only use the smallest amount of oil necessary to cover the filter as using too much oil will bugger up the MAF. Some people even recomend you just buy a new filter rather than the cleaning kit as the new filter is good for 50km miles before cleaning anyway and when you deduct the cost of the cleaner the filter is only 50 euro more and there's no risk of MAF failure.
We make high-flow cotton air filters for most vehicles. Our air filters drop into your cars air box in 5 minutes or less, often with no tools required. Weve sold millions of our cotton air filters since 1969. We even back up our replacement air filters with a 1,000,000 mile limited warranty."
When you weigh up the cost on air filter cleaner and air filter oil (which will last several services) against the cost of replacing your K&N filter every 50,000 it makes sense to clean it and re use it for as long as recommended. Unless you've money to burn
[quote author=stevo link=topic=14275.msg176575#msg176575 date=1239441780]
whats the best way to clean a K&N panel filter, do i need special cleaner or will petrol do??
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you should never use petrol to clean a cotton filter, it affects the filtration property's of the filter.