Can I leave my GPS device in a hot car?

The answer is definitely a “no”. Just like any other electronic devices, heat can do a lot of damage; it not only can destroy the GPS device’s internal components but also its memory card even if you leave it somewhere away from the direct sunlight. Actually, it is the heat that you should avoid.
Malfunctions
Heat first causes your GPS device’s software to malfunction and you may notice the device shutting off unexpectedly or presenting incorrect information. If you continue to leave the GPS device in your car, the heat begins to damage the device’s internal components, including memory card, if present, power supply components and the device’s circuit board components. Once heat-related damage occurs, repairing the device is impossible and you will have to replace the GPS device.
Direct Sunlight
Never leave your car’s GPS device in direct sunlight, including leaving the device mounted to your car’s windshield, dashboard or console surfaces. Direct sunlight raises the device’s internal temperature faster and causes damage to occur sooner. The sunlight can also discolor your GPS device’s LCD screen, casing and mounting bracket.
Car Storage
Even placing your GPS device under your car’s seats or in the glove compartment does not protect the device from heat. Heat builds up in all areas of your car including the trunk, center console and overhead visors. Your car’s internal temperature only increases on a hot day and your GPS device become hotter and hotter.
Storing
On a hot day, not mount your car’s GPS device and store the device in a cool, dry place outside of your car like in your home or office. If you are traveling, store the GPS device in your shoulder bag, messenger bag or similar bag until you are ready to use the device again. Do not store your GPS device in an area with high humidity or around water or other liquids that can also damage the device’s components.