I'll have to agree with Matt26, there are better ways to remove vehicular glass. The one exception might be for the first responder operating from a private vehicle prior to the arrival of emergency apparatus. However, the uses are limited at best. You can probably purchase a spring loaded punch, small prying device, and a "tool box hand saw" for a lot less money.
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Forever... A long time to be dead!
Staunch advocate of the First, Second, and Fourth Amendments