The check engine light is always coming on. I've spent as much money on the car getting it up to par performance than I paid for it. Major issues to look out for: engine harness, air mass meter, oil leaks, valve jobs, suspension issues, etc. Here I thought that Mercedes would be reliable and low maintenance. Some things must be learned the hard way. It's a nice car to take on the highway, but it does lack acceleration at times. Requires premium fuel and synthetic oils are not gonna keep one from spending on its up keep. Overall, I'm sorry I was deceived by a supposedly top German auto maker. Sure, it's better than most American cars in its class, but it will be my last Mercedes-Benz!