I bought my 2004 RX8 back in april or may and its still in the garage. Just jave body work left before i can drive it. There was a misfire code and when I bench tested tge coil packs they were done. I ordered the kit drom NP Boosted. They forgot to put the spark plugs in the shipment but they were very easy to contact dor a resalution. The kit came with no instructions and took about 90 mins to install in the car. Obviously the misfire is gone.