My sweet Lori’s 2007 Ford Focus came with a “permanent” air filter, “suitable for the life of the car” by one suggestion. After we had had the car a while, I knew we wanted to keep it running long, long past Ford’s glorious preferences, so I started looking for options. One well-known vendor sold an aftermarket air filter box for about $480. This seemed a bit high to me for a mildly complicated piece of plastic, so I looked further. And lo and behold:
www.rockauto.com/en/moreinfo.php?pk=8624632&cc=1433435&pt=11160&jsn=1
Highly recommendable, and $78 at this writing. I saw some reports which said it made things a tad louder; au contraire I must report, Sweet Lori’s little car is now quieter, much smoother, better power. Yahoo!