Can't use symbols

app/models/vehicle.rb

@@ -28,9 +28,9 @@ class Vehicle < ActiveRecord::Base
     if vin?
       decoder = Edmunds::Vin.new('2dheutzvhxs28dzukx5tgu47')
       vehicle = decoder.full(vin)
-      year = vehicle[:years][0][:year]
-      make = vehicle[:make][:name]
-      model = vehicle[:model][:name]
+      year = vehicle['years'][0]['year']
+      make = vehicle['make']['name']
+      model = vehicle['model']['name']
     end
   end
 end