More than 90% of the cards on the market wouldn't be warranted for use in dashcams, doesn't mean they're not suitable, for sure there are some models that I wouldn't use in a dashcam though
The warranty (for the SanDisk Ultra cards for example)
specifically excludes their use in dashcams and home security installations (where the card is being constantly written to).
The card may indeed work, and work fine for a period - be that days, weeks, months or years - but the fact that the manufacturer of the card will not guarantee it for use in dashcams suggests that they expect the card to fail at some point (I'm guessing sooner rather than later). As such, you use a card like the SanDisk Ultra at your own risk.
Please understand that I don't have any particular axe to grind here and I am not against SanDisk Ultra cards at all (except for this particular application) it is just that I have particular experience of this particular card for this particular application. Despite specifically marketing the High Endurance cards as suitable for Home Security and Dashcam use it doesn't mean that the card will work faultlessly. In any event, be it a high-endurance card or not, you are using the card (and dashcam) with the assumption (hope?) that should you have the need to recover the video off the card, you will be able to do so without problem, however nothing in life is absolutely guaranteed in this way (and ultimately can't be absolutely guaranteed because of quantum physics and uncertainty). Failures, be they one in a thousand, one in a million or one in a billion will occur, you just have to hope that you aren't the unlucky person that the failure happens to. Like the lottery, the odds may be one in fourteen million, but folks
do win the lottery (sadly, just not me).
Anyhow, I offered this information to the forum as a result of what I uncovered when I bought my dashcams. Whether you agree or not, that is your choice as is the choice to use the high-endurance cards or not. In my case, for an extra degree of 'confidence' (for want of a better word), I chose to use the high-endurance cards.
Art