I'm with CJ3 here...so long as you plan on actually keeping your vehicle for the entire term of the extended warranty you choose, they can end up being well worth it. All it takes is an ECM going bad, these totally electronic dash boards and computerized HVAC systems fizzing out, or some of these high tech airbags as mentioned, and a $1000-$1200 warranty has paid for itself in one fell swoop.
I bought the whole sh-bang Platinum warranty before I left the lot with my new 2008. I want to say it was $1200 or so? In that range somewhere, I honestly can't remember at this point. I know I simply put enough down to pay off that amount, and only put like $1200 or $1500 down...I try to pay the tax and extended warranty at the time of purchase so I am not financing those items...Although, I got 0% financing on this one and may not have this time...lol