diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,8 @@
 # Changelog for tesla
 
+# Release 0.1.0.1
+
+A more informative exception is thrown from `runNamedCar` when an
+unknown car name is given.
+
 ## Unreleased changes
diff --git a/src/Tesla/Car.hs b/src/Tesla/Car.hs
--- a/src/Tesla/Car.hs
+++ b/src/Tesla/Car.hs
@@ -32,6 +32,7 @@
   vehicleURL, authInfo, vehicleID
       ) where
 
+import           Control.Exception      (Exception, throwIO)
 import           Control.Lens
 import           Control.Monad          ((<=<))
 import           Control.Monad.IO.Class (MonadIO (..))
@@ -83,12 +84,26 @@
 runCar :: MonadIO m => IO AuthInfo -> VehicleID -> Car m a -> m a
 runCar ai vi f = runReaderT f (CarEnv ai vi)
 
+newtype BadCarException = BadCar String deriving Eq
+
+instance Show BadCarException where
+  show (BadCar s) = "BadCar: " <> s
+
+instance Exception BadCarException
+
 -- | Run a Car Monad by looking up a car by name.
 runNamedCar :: MonadIO m => Text -> IO AuthInfo -> Car m a -> m a
 runNamedCar name ai f = do
   a <- liftIO ai
   vs <- vehicles a
-  runCar ai (vs Map.! name) f
+  c <- case Map.lookup name vs of
+         Nothing -> throw $ mconcat [show name, " is not a valid vehicle name.  Try one of: ",
+                                     show $ Map.keys vs]
+         Just c -> pure c
+  runCar ai c f
+
+  where
+    throw = liftIO . throwIO . BadCar
 
 -- | Giant blob of VehicleData describing all known state of the vehicle.
 --
diff --git a/tesla.cabal b/tesla.cabal
--- a/tesla.cabal
+++ b/tesla.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 8cdeecd446c907e59d314404de69be9fd58fd7e9276d2d0e1b34f4f222b77c1f
+-- hash: bc86432b798b84de1d75a14ba3e27975fe6c0c2431111c061bfcd48bdf851848
 
 name:           tesla
-version:        0.1.0.0
+version:        0.1.0.1
 synopsis:       Tesla API client.
 description:    Please see the README on GitHub at <https://github.com/dustin/tesla#readme>
 category:       Web