Coilovers are an excellent upgrade for any Evo to enable flatter cornering and improved handling. The advantage of coilovers over standard springs and dampers is their adjustability. Some of the more sophisticated coilovers allow multiple adjustment for bump and rebound settings as well as ride height. You can have a low, hard ride for use on track where stiffness is desirable to allow less body roll and a softer setting for on the road to absorb bumps and potholes. Ohlins, Tein, Nitron, Driftworks, Cusco and Gaz are all respected manufacturers in this respect and offer coilovers for every budget.