sure, it'd be dangerous. doesn't need to be a single 50 bullet burst under the SR4 rules for that, though.

i think 5 separate 10 round bursts is quite scary enough, personally. in general, if you're not turning something into a fine red mist with that, it either doesn't have any red in it or you wouldn't hurt it even if it was a single gigantic 50 bullet burst.

No one said you couldn't, there is a planned rulebook that I guarantee you will cover multiple vehicle weapons and linked weapons systems, it just hasn't come out for this edition yet.