I owned a 2004 RX8. The car is a good looking, clever design that has good weight distribution and excellent handling. I always thought the platform was a good fit for a flat 4 engine. The Renesis engine has seal lubrication issues. Oil injection is problematic from an EPA perspective, so Mazda is trying to inject the minimum amount of oil at the RPM ranges that EPA looks at. The EPA allows more oil injection at higher RPM levels, which is one reason why redlining the Renesis is beneficial. Redlining also helps to reduce the deposits at the exhaust port. In the RX7, the apex seals passed the ports. In the Renesis, the side seals pass the ports, so the side seals are the usual failure. Premixing TCWIII or other 2-stroke lube helps greatly. My motor responded well to premix, immediately running smother and revving easier. I just started it too late to save the seals. The RX8 boards have a never ending discussion about which oil is better. There is no magic solution to Renesis engine longevity. If you purchase one, set aside funds for a motor rebuild and enjoy the ride!