A filter for exhaust gases produced by an internal combustion engine, and a method of using such a mat on a vehicle. The filter is a mat of fibers enclosed within a metal gauze. Preferably, the mats are corrugated and spaced apart within a housing such that exhaust gases will pass through the mats sequentially. The fibers are wettable, and in use are preferably located a sufficient distance from the engine such that the mat is wetted by condensing water or other liquid in the exhaust gas. Preferably also, the filter is adapted for coupling to an existing exhaust pipe opening.