I've been on this forum now for almost 10 years, and you would be out of your mind to buy a GMPP warranty from anyone other than Ken.
I bought mine from Ken on my car, and now just called Ken because my wife and daughter are out in California where they purchased a used 2004 from the local Chevy/GM dealer (long story).
At the last minute (after we had negotiated the deal long distance), the dealership's finance guy soaked my wife and daughter for not retail price on a GMPP, but 50%over suggested retail.
Thanks to Ken, we're canceling the warranty, and saving my daughter (college student) a lot of money.
Not only will I buy all my warranties from Ken (Bob already hsas my parts business), but my next Corvette is Ken's as well.