May come in handy if someone blocked your car on a parking and you don't have time for the tow truck to arrive. Or when you're stuck on I-95 during a major snowstorm.
I'm not claiming any of these are worth the complexity and cost of rocket boosters, but there are uses!
I guess as long as we’re thinking up increasingly outlandish use cases, how about being able to park at the top of buildings when there are no parking spots available. Or being able to hop over the parking gates at theme parks. What about bypassing the speed limit at school zones or hopping over stopped school buses. Oh and no more waiting for draw bridges or railroad crossings. The uses really are endless!