I have bought a Pipercross for my MX5 and have just pulled out the instructions. There are 3 different sorts on the instructions:
- Race Filter - suggests not suitable for road use - but no details of how regularly should be cleaned
- Oiled filter - needs servicing every 20,000 miles
- Dry filter - which presumably is the one for this car (mine is not oiled, so again, presume it is this one) - needs servicing every 20,000 miles.
Hope this helps. Can upload a picture of the care instructions if anyone is interested…