Credits: Vanhela, darkdraggy and RationalPsycho
Get om0, start leap and bound mission, wait for the rampage to fail and enter the marker to watch over lance. After the cutscene, jump off, get in the vehicle you left before and once the game tells you to help lance, drive near him, then drive to the hideout and activate leap and bound again, once the speeder is about to pass under the bridge which connects starfish island and little havana. Also, do not skip the cutscene, otherwise, you might get stuck in a loading loop. If the game didn't froze, skip the cutscene. Once you regain control over Vic, go to the place where the boat is. If you activated leap and bound at the right time, the boat will drive in circle around the bridge which connects viceport and washington beach. Now try to jump on the boat. Once the shark gang member leaves the boat, take control over it, let it parked somewhere safe and pass the left storyline missions to unlock the vice city beach and prawn island. Now let the boat near the beaching point near clymentus suite, go get an ambulance, go back in the boat and beach it. Now, using the ambulance, carefully push the speeder2 to clymentus suite, store it in your garage and it's yours
-Note1: this is not a normal speeder. Its ID is 185, unlike the normal speeder, which has ID 215. Also, in Bradygames guide, it's known as Ambassador. Another differences are: no name is shown in bottom right when you take control over it, it is much faster than a normal speeder and it tends to " fly " when driving south.
-Note2: the boat is marked before storing it, this being the reason why it's obtainable. After storing it, it gets unmarked
I apologise for the messed up quality of the video, but I forgot to change the graphics settings back to Vulkan