Sixt seems to favor a licensing market entry strategy. The problem is that they threaten to dilute their brand image: Offering European visitors large cars and SUVs they can only find in America, and introducing American customers to European performance cars. This is especially a problem as Sixt expands beyond traditional sunny vacation areas with lots of European tourists into the American heartland.

Ex, Another thread implied that some franchises (ex CLT) are stocking generic, high mileage used Japanese cars presumably bought at auction from other rental companies. There is no unique customer experience that warrants paying more for them than, say, Priceline or Rent a Wreck.

There is also the oversight that regional one-ways are very common between smaller US cities with expensive and infrequent air service. Hertz, and to a lesser extent National and Avis, have a lot of expertise handling this demand, by strategically placing corporate stores there. Sixt initially missed out on this between CLT and ATL.

This article suggests Sixt might have learned. Interestingly, they now allow one-ways between CLT and ATL, and between Knoxville and ATL. They might set out on the right track, if they can set up a network in the Midwest, owned by the same franchisee, that can therefore accomodate one-ways.