Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Constant lock ups

I bought this unit as a Christmas present and it has proved to be a four month headache.The unit constantly locks up while driving. I've returned this once and the new unit does it just as much. And it rides in a fairly new Cadillac so its not like there is much jarring.Now the mounting bracket is broke.Save your money, buy another product.