When you're making good time in your car, pulling over to relieve yourself means all those jerks you just cut off will get ahead of you, requiring they be cut off anew. Solve this timeless problem with a RoadBag.
Brought to you from frighteningly inventive Germany, RB's a monster-burrito-sized disposable sac that incorporates the same no-leakage system fighter pilots use to avoid mid-dogfight sloshes. Operation's easy as urine: unscrew the lid, then direct what had once been a Big Gulp into the bag, where "superabsorbent polymers" will bind your business into an odorless, solid gel. Overflow's not a problem, as the average man's volume is 300-500ml and the RB holds 700ml -- enough leftover space for that clotted frappuccino responsible for your car's choking aroma.
Pop a few in your glove box, as RoadBag can be stored indefinitely in a cool, dry place, but heed their warning and "do not swallow the superabsorbent crystals", or you'll face the classic RoadBag dilemma: whether or not to lie to the EMTs that you thought you were drinking a Capri Sun.