In another thread, First Alert's Tundra fire extinguishing spray was mentioned. Any thoughts on if this would be a good alternative for cars?

From a size perspective, it seems like it could be easily stored in a glove box or console, eliminating the whole mounting issue.
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Victory awaits him who has everything in order — luck, people call it. Defeat is certain for him who has neglected to take the necessary precautions in time; this is called bad luck. Roald Amundsen