Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Stops working after 18 months unless you buy new maps!

I bought a Garmin 18 months ago. Recently it notified us that the maps needed to be updated. We thought this would happen via satellite automatically. Instead, we were directed to the Garmin web site -- to PURCHASE the update.To get the map update downloaded to the device, we have to pay $70! In the mean time, the device is totally worthless.