Slemker Buick GMC has a great selection of new and used Buick and GMC trucks, cars and SUVs to choose from. If you are looking for a Buick or a GMC dealer in Eaton or Middletown, OH, you have found the right place! You can browse your area Dayton Buick dealer’s selection of new vehicles and GM Certified Used Vehicles here on our website. Your local Dayton GMC dealer’s inventory is updated daily.