[elhigh]

It doesn't have to be any kind of high grade sewer pipe, 2" PVC is strong enough to hold a hard vacuum. A 30" length of 2" PVC is equivalent volume to that 16.4 oz. canister and rigging fittings to hook up to it should be child's play. There's plenty of room under the bed of your truck to array as many pipes like that as you want.

Barring that, for a few bucks and a quick trip to Pull-a-Part, you could have as many vacuum reservoirs as you wanted and array those on a rack under your truck. No problemo.

But dude: exclamation points. Chill. Or as you say, chill!! You're killing me over here.