San Francisco Airport

Oakland Airport

San Jose Airport

There's a list at www.nationalcar.com, Emerald Club, Emerald Club Exec Select/Aisle Service locations.

A midsize reservation entitles an Emerald Club member to pick from the Emerald Aisle at locations so equipped. You might find Full Size cars, a minivan, or a full sized crossover on the Aisle - but it will be more likely full of midsize vehicles like Chevy Cobalts, Chrysler PT Cruisers, and Nissan Sentras. It would be far safer to reserve a Full Size and pick from the dedicated full size row (or self-downgrade to Em Aisle if you see something you like).

Again, you're facing buying a choice of vehicle with the Emerald Aisle concept at the cost of airport taxes and fees because it's only at airports that Emerald Aisles are found.