trick to doing it is calling a taxi LOL
Haha, yes a taxi would also do the trick.
BTW: There is an in-game website with a map of all the stunt jumps. Use your phone and search for 'junk' or type www.junkenergydrink.com, then click the "adrenaline junkies" button. Unfortunately it isn't interactive, so you'll have to keep track of which ones you've completed yourself.