2000 Buick Regal Owner's Manual - Page 261

CAUTION: Operating the engine with the air cleaner/filter off can cause you or others to be burned. The air cleaner not only cleans the air, it stops flame if the engine 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 the engine with the air cleaner/filter off. Passenger Compartment Air Filter The passenger compartment air filter is located underneath your hood just below the windshield wiper arm, on the passenger's side (underneath the air inlet grille) of the vehicle. NOTICE: If the air cleaner/filter is off, a backfire can cause a damaging engine fire. And, dirt can easily get into your engine, which will damage it. Always have the air cleaner/filter in place when you're driving. The filter traps most of the pollen from the air entering the air conditioning module. Like your engine's air cleaner 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