I don't believe in extended warranties but if you really get one then get it from the vehicle manufacturer.

Several years ago, our friends bought a used BMW from the local dealer. The salesman pushed the aftermarket warranty real hard, even claiming that BMW didn't offer an extended warranty on used cars! I advised our friends to go to another BMW dealer, bring along the VIN of what they were buying, and get a warranty quote from them. It turned out that they bought the BMW warranty from the other dealer for less than the local guy wanted for the aftermarket warranty. The local salesman was pi**ed! All's fair in love and war...