Well, besides being rear-ended after I bought my car I had my first problem this week. The SES light came on but I didn't notice anything visibly wrong and the engine ran fine. So today I take it to the dealer and they run the codes. PO304, #4 Spark Plug fouled. So I roll out of the dealer with a new spark plug free of charge and a handshake. Gotta love those Service Advisors who don't ***** about mods.