It is clearly car orientated, but with regards to alloy, you can bond a Landrover wing on with it. I don’t know why it doesn’t appear in general building products, apart from as you say the need to withstand vibration. However, f you bonded two sheets of alloy together with it, they would be impossible to separate, without destroying them. It’s totally weather resistant, I stuck a boot spoiler on a Camaro ten years ago, and it’s still there, you’d bend the boot before you got it off. Whether or not it’s the right thing to use, I can’t say, but I can say it’s the best.