1998 Buick Regal Owner's Manual - Page 282

Passenger CompartmentAir Filter Operating the engine with air cleaner off can the cause you or others to be burned. The air cleaner not only cleans air, it stops flameif the engine the backfires. If it isn't there, and the engine backfires, you could be burned. Don't drive with it off, and be careful working on engine with the the air cleaner off. The passenger compartment air filter islocated underneath your hood just below the windshield wiper arm on the car's passenger side (Underneath the air inlet grille). I NOTICE: If the air cleaner is off, a backfire can cause a damaging engine fire. And, can easily get dirt into your engine, which will damage it. Always have the air cleaner in place when you're driving. The filtertraps most of the pollen from the air entering the air conditioningmodule. Like your engine's air filter, it may need to be changed periodically. For information on how often to change the passenger compartment air filter, see "Maintenance Schedule" in the Index. 6-18