<prompt> Human: I bought a 2011 Mercedes with 54000 miles a month ago. Today I went for the license plate and driving back home the engine light turned on. Supposedly Autonation have a 90 days guarantee but Im concerned if they decline fix it or just turn off the light. What are my options? What should I do?  <response>: Well..the car isnt one month old, its 7 years old.However, go to AutoZone and get the codes read. Then take it to the dealer and have it addressed. If the light comes one again, get the codes read again. If its the same code, you have some ammunition for going at the dealership for not fixing the issue. 