I'm a retired truckdriver now but I use to get randoms all the time. They were'nt really randoms the boss knew I smoked and kept trying to catch me.lol
I just kept the bottle of synthetic urine in my pocket with a heat pad and when I got the call I would activate the heat pad and put them both in my crotch. Then just stall for 45 minutes to an hour till the pad warms the urine up to temp. Don't have to be in a hurry. They're paying you by the hour anyway.