K&N filters rock, I wash mine out in the sonic tanks at work and never bother with oil other than a quick squirt of maint spray.
My current filter is upwards of 60k miles and on its third Mk3.
Paid about £30 for it 6 years ago so its paid for itself and bought me a beer

As for performance, it wont do dick on its own but allows you to exploit other areas better
Got some more pics somewhere, but i have been working through my intake in prep for a hot cam.
Gone away from drilled box and fitted bigger bore intake into original wing compartment (minus inner part of grommet, pipe on in 90mm elbow is for show only you need to cut the end at an angle so you dont seal off against the inner wing

Leave hood part of box alone fecking with this makes the car run pants.
I have also opened out my maf housing, dont feck with the Ali baffle or sensor tunnel

This one is now polished up gleaming with a new custom baffle.
Throttle body is now fitted, polished and enlarged+ matched to fit intake Manifold better.
Tip, use thin blade like half a power saw or strip of metal and heat it up very hot (be careful)
cut through ribs inside the base of the air box to smooth off, makes it easy to tidy them afterwards

Got a nice exhaust fitted and a sport cat to go on, found a cat only part which i need to weld into the system cost me £80

Car revs up quick and feels more responsive, cam will come when I can find the money for now PB cam will suffice
Is it worth tuning an 8v? dont care it gives me something to do and i spend some quality time with my dad in his workshop also its cheap fun.

