there's no mitigation for meth heads.I'd be worried about that very visible thing walking off. Even if it is the cheapest box/woofer there is, some dummy will smash your window and cut the wires if they think they can get $20 for it. Maybe you have that mitigated already...
besides major aesthetics issues, yes, I would not advise doing this because of the very high risk of smash & grab theft. redesign the box to fit under the seat, or buy a prebuilt box. (there's now at least 3 options.)
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