I purchased a used 2007 ZR6 and have exactly the same issue. I did purchase from a dealer so it's going back to them tomorrow for them to 'assess'. Terry Shields did do a service on it and quoted the same price as ashren totaling $8,500 including labour! The guy at Terry Shields was very helpful and did tell me that it may be fine for 6 to 12 months before needing work. I'm not sure how I will go with them but it may have to be submitted to Fair Trading to get an outcome. It is a quite surprising for Toyota to have such a huge issue without a recall, particularly when it is such an expensive job. Ceeber, how did you go?