We do the 30/30, 30 feet or thrity seconds which ever comes first.....lol. Seriously though we also do the 12/12. No warranty on labor or parts if used even if we supply it. I offer that option to my customer but make sure they understand. After reading some of the situations posted above I see a common situation which can usually be avoided if your service writer/counter person does a good job explaining what is and isn't covered when an job is performed. We all have THOSE customers who expect something for free, but once again my service writer handles those situations easily due to the fact that upon the initial job everything we see is documented on the customer invoice. As for what Alfred just typed, we won't let customers tell us to replace parts without US diagnosing. If they wont pay my diag fee then I don't want them as a customer. I have seen first hand who loses when a customer self diagnoses his vehicle and supplies a part. If it doesn't work then the shop who did the work doesn't feel good about the repair and neither does the customer. Those customer usually leave and give negative publicity. Although it wasn't the shops fault, who pays the price when slandered. My .02c