If it's a third party warranty, then there is no way.

If there happen to be an extended warranty from the Mfg,simply submit the vin # to the service dept to check.

I thank you for this questions as it made me realize to add another entry into the website about how buyers can find out if there is warranty in place " example "

If your buying a pre-owned Ford, simply contact any Ford dealer service dep't in North America, and if there is an extended warranty in place by Ford, purchaser will know...