-( Story related, cannot be missed )-
In the stadium, you'll find a souvenir salesman offering, above everything else, a mechanical bunny. Tempt the salesman by asking about the souvenirs on the wall (by choosing them directly rather than during conversation) and, as he checks them out for you, make off with the rabbit. This won't get you the trophy, though... FOOLED YOU!
The trophy is misleading. While it says to snatch "the bunny", it won't register until you snatch the entire collection of robot bunnies. So there's a bit more you'll have to do. Take control of the RC car and attempt to drive it off screen to the north. It'll return and power down. Now, go back to the main screen and drive your bike off the road (where the guard rail is broken, with a road behind it).
You'll come across a minefield at the end of the path, the Vultures' lair on the other side. Take out the bunny and use it on the field, watching it carefully. As it explodes, it'll leave a battery for you to take back to the RC car. Install it in the vehicle and drive it north once more. Navigate it towards the turnstile to occupy the salesman. Now you can take the box of bunnies behind the counter and prepare to sacrifice them for the greater good!