After hearing many horror stories about warranties I decided not to bother. It seems that more often than not, the insurance company will try every trick to get out of paying - just like every other insurance !!
I decided my best option was to spend a year getting to know different F dealers, listen to what other people said about them. Reputation is very important. Once I had decided on a dealer, I felt it was important to let them know that they would get all future servicing work from me if they looked after me. More importantly, when you have found your dream car/s, pay for an expert to give it a very thorough inspection. I can only speak from my own experience. The 328 I bought only had a 3 month warranty, the rear o/s wheel barings went after about 6/7 months, although they had started making a noise after about 3 months and I had notified the dealer, but the dealer fixed it FOC when I took it in for it's annual service. I will be taking it back there for it's next service and any other work that is required.
If you are based in the UK, I am very happy to recommend Nick Cartwright in Derbyshire, and have met many other Midlands owners who speak very highly of him and his team.