Against my better judgment, I bought an extended warranty from Guardian Warranty Corporation when I bought my TDI. They did pay to have my radiator replaced without any hassle, but they didn't cover fluids or taxes though, so it still cost me about $300. (more than it cost me total to replace the radiator in my Nissan, incl. all parts, labor & taxes.) I say "against my better judgment" b/c consumer advocates tend to frown on warranties altogether, but if you do purchase one they always say to get extended warranties only from the manufacturer of the car and not from any third party providers.
In any event, if you do get an extended warranty you want one that is an "excluded items" warranty (everything is covered except what they list as exclusions) rather than a warranty that only lists what is covered. With the latter, the warranty provider can find ways to weasle out of coverage much more easily.
Also, if you are a member of a credit union, check with them to see if they work with Car Solutions. The Car Solutions warranties are supposed to be among the best 3rd party warranties. But they only work with credit unions.