What remedy do I have against an independent Porsche/BMW repair shop that has done some very shoddy work the past couple years? Most of this poor work did not come to light until over a year later when I took these cars to other shops that uncovered their mistakes. Example-Replaced iginition module in porsche-Charged me $879 for $350 worth of parts. Also did not install turbo correctly (leaked oil due to not using a gasket) and a host of other just poor quality work. I spent about $13k over three years with them. I thought my BMW was running a bit hot during the summer and wanted it checked out while it was in the shop. Replaced the radiator without even asking me if I wanted to spend the money. There are shops that know what they are doing and shops that just start replacing parts and the customer pays to educate them on repairing cars. Wondered what the options are prior to me confronting them in person. Better Business Beureu? Stand outside their shop with a sign that warns potential customers that they might be getting ripped off? Other than the exorbant mark up on some parts I am not sure if they are just incompetent or theives. Suggestions?