Several here are shopping dealers. Does picking dealer A affect the ability to take the Prius to Dealer B (closer) for service, like the free oil changes?
Think about it. People sometimes buy a new vehicle and then for unforeseen circumstance have to move....sometimes great distances. You can buy your Toyota from any Toyota dealer...and then choose any other Toyota Dealer for service.... If a local dealership is offering a dealer specific freebie...like free oil changes or Nitrogen Tire Refills...then other dealers obviously don't have to honor that private dealership offering. But for all warranty service, or just plain service...you can take your Prius to any Toyota Dealership.
The dealer you don't buy from will never remember you... Besides, you won't be dealing with the salesperson.. you'll be going to the service dept. You can get them serviced at any Toyota dealer.
Some dealers give special preferences when servicing customers who buy from the same place, but other than that, all of them will service your vehicles per the factory recommendations.
Agree with the likes of the Prius perhaps. But never had that feeling with getting my '99 New Beetle or '03 Baja from Stolhmans VW/ Subaru in the Tyson's area. Doing some research on Toyota dealers in the Northern Virginia area after buying my 2012 in Laurel MD (a 40 mile ride away from where I live). IMO working in sales and service; a relationship is good to have.