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Being that the flat-bed truck doesn't carry cargo internally, I'm fairly certain the BA would survive its destruction (albeit, hoofing it, as described). The trucks are so cheap, I think they'd still be worth the investment.
Let's say you're in melee combat against 2 or 3 'Mechs, you know your 'Mech is going to be destroyed anyway, why not blow it up and damage the 'Mechs attacking you?