I just picked up a '08 Tahoe Z71 yesterday, it is a certified pre owned with 50, ooo miles. I have 12 months-12,000 miles with the CPO but would like to possibly explore an additional extended warranty, anyone have any good advice for me? I will keep this truck for a long time, my current Trailblazer is a 2002 that has 290,000 an I bought it brand new.