Originally Posted by
ISTFlyer
I presume the problem is one of the two below;
1- Upgrades are not allowed to use Exclusive Drive.
2- Not all itineraries to US&Canada destinations qualify for Exclusive Drive. Where is your point of origin ( first point of departure )? This might help.
1. It's a full fare J.
2. On a single itinerary I'm doing BTU - KUL - IST - IAH and back