Thanks everyone for your support. I've only used premium unleaded fuel from "quality" stations. I've only used the synthetic oil recommended from the manufacturer; that's what's so puzzeling to me. I've followed everything to the letter and was expecting for this car to last much longer without these kinds of issues. As far as the oil consumption issues, I have been addidng at least a quart a month, but I do a lot of highway driving. lately it has gone up to a quart every two weeks...