Just buy the extended warranty if you're sure you will keep the car that long. Long-term reliability is typically very good on these cars, but just ONE bad problem on any of the cars you are considering can leave your wallet much lighter. High pressure fuel pumps, anyone?
With BMW (and perhaps the others) you can even wait until you are about a month away from your original warranty expiration to decide whether to purchase the extended version.
Just wait until you're with the finance guy, grumble a bit good-naturedly about some minor part of the purchase experience, mention how you HATE giving anything but the highest marks on the post-purchase satisfaction survey, and you're almost certain to be offered a reasonable discount on the extended warranty.
Personally, I never buy them for my "fun" car anymore, since I'm at that age where trying something new every 4 years is something I really look forward to.