HP dv6500t + Costco warranty + Amex warranty

I've decided on the dv6500t. I can purchase through the HP APP, but Costco looks better due to return policy and warranty extension.

Now my warranty question. I see threads discussing credit cards (including American Express) that double the original manufacturer warranty up 1 year.

Costco doubles the manufacturer warranty to 2 years. If use my Amex card, does it now become 3 years?

1 HP + 1 Costco + 1 Amex = 3 years?

Or does the Costco and Amex benefits run concurrently, i.e,

1 HP + 1 Costco OR 1 Amex = 2 years?

If this is the case, I'd purchase 2 year HP warranty through Costco for $98 so that Amex would tack on a 3rd year.

*** Has anyone looked into this possibility? ***

 

any credit card will only double the manufacturers warranty. Amex card will not come into play.

 

Costco uses HP's warranty service. If you used Costco's American Express Card then I don't believe that would come into play. I believe you have to register with AMEX for the extended warranty. Why don't you ask Costco?