Cityless help

Hello, I am doing a personal challenge of where I thought it would be funn-I mean nice to do all other challenges before opening city trial proper. I have managed to do all challenges for road trip, air ride, top ride, and all seemingly possible city trial ones (while I am not allowed to use city trial proper, stadiums are allowed, because from a certain perspective they can be seen as being more akin to road trip segments), and have moved onto online. However, there is two challenges that thus far have eluded me, making me unsure if they are possible without city trial. These are >!fly continously for 15 sec. with Jet Star!< and >!eat a maxim tomato!<. The former I feel is just out of reach, getting seconds off no matter what rider I use, so I assume it is impossible without using city trial. However, the latter I honestly don't really have a clue on the parameters for where to get it. If someone else is able to confirm that they are impossible with my restrictions, or how to get them if not, it would be much appreciated.