Not very knowledgeable responses to questions I had. Thankful that I have other mechanic resources in town that I can ask for advice in such situations. Service person had same "sales speak" that I've experienced from a salesperson at this dealership in the past. Also, the diagnosis charge of $86 was not applied to the repair bill like other shops I've dealt with in the past. Ouch! This was a VERY EXPENSIVE spark plug change. Not likely to return.