I would expect most memory cards to handle some higher than normal temps because they are inserted in a case that somewhat insulates them. Unfortunately being on the dash, they do not get any real benefit from the AC or Heater in winter. Residual heal from the dash cam will add to the operational heat picked up from the cam electronics. Expect most memory chips to have shorter lifetimes under these conditions. Once the elements start to fail , you will notice streaks in your cam still pictures or video interference in the cam files . Once you see that , replace the chip immediately to insure you have reliable storage media. I would recommend to watch for aberrations' after a year depending on amount of usage.