The Postal Service’s new delivery vehicles aren’t going to win a beauty contest. “You can tell that (the designers) didn’t have appearance in mind,” postal worker Avis Stonum said. Odd appearance aside, the first handful of Next Generation Delivery Vehicles that rolled onto postal routes in August in Athens, Georgia, are getting rave reviews from letter carriers accustomed to cantankerous older vehicles that lack modern safety features and are prone to breaking down — and even catching fire.