Originally Posted by nsx
I accept the very reasonable presumption that Priceline's payment to the rental car company is not your DC. (If it were, Priceline couldn't make a profit!)
The fact remains that DC has earned essentially the same merchant discount from your Priceline charge as DC would have earned on the amount Priceline paid the rental car company. In my opinion, DC has no principled financial reason to exclude Priceline rental coverage.
Futhermore, if the terms do not spell out what happens for opaque bookings, I would expect any cardholder who challenges a denial of coverage to win.
I wish you the best of luck and hopefully, you will also obtain a discount on the legal fees that you will incur for challenging the denial of coverage.
P.S. -- You may want to check out the following before pursuing your quixotic quest for coverage.

@:-)
Automatic primary coverage, anywhere in the world (except where prohibited by law),
any time the entire cost of a car rental is charged to a Diners Club Card.
http://www.dinersclubus.com/dce_cont...ravelinsurance
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To get coverage:
•
Initiate and pay for the entire rental agreement/contract (tax,
gasoline, and airport fees are not considered rental charges) with your Diners Club Charge Card.
If a rental agency promotion/discount of any kind is initially applied toward payment of the rental vehicle, at least one (1) day of rental must be billed to your Diners Club Charge Card.
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What is NOT covered:
•Vehicles not rented by the Diners Club Charge Cardmember or
authorized user on the Diners Club Charge account.
Submit the following documentation within 180 days of the incident or
the claim will not be honored:
– Completed and signed claim form.
–
Diners Club Charge Card receipt showing the rental.
–
Diners Club Charge Card statement showing the rental.
http://www.dinersclubus.com/us/en/pd...arge_terms.pdf
You are most welcome.