Do the Dancing Part like normal and get in the EC2 Pony with EM Off-Road Wheels like you normally would.
Start OG Loc's first Mission Life's a Beach and go to the Beach Party as instructed.
Open, close and open the Garages where they're stored, because if you don't do that the Game won't acknowledge them being in the Garage as they're Mission Scripted Vehicles and will despawn if you Save without checking them after Passing the Mission. It's nice to do that as there is a EC Yellow Forklift during Breaking the Bank at Caligula's which is unobtainable, but I wouldn't do that as I like to keep the obtained Special Vehicles as original as they appear during the Story Missions. The Mule with the EP Property is Inferior though, as you can make a Mule EP/FP using the EP/FP Property, nonetheless, it's still a Special Vehicle though I wouldn't care obtaining it. If you really wanted to, you can make this a BP/EC/EM Forklift using the EC/EM Conversion Tricks later on. to know how to obtain the EC Green Mesa with EC Green Roof, BP Forklift, and EP Mule all at the same time. If you really wanted to, you can make this a EP/EC/EM Mule using the EC/EM Conversion Tricks later on, or even a EP/FP/EC/EM Mule if you use the Designed EP/FP Mule from Gray Imports. It's your choice if you want to get it or not, or if you want to obtain a EP/FP Mule during Gray Imports instead. AP Vehicles can only be destroyed by tipping it upside down, using a Bomb Shop, using the Blow Up All Cars Cheat, if a Tank bumps into the Vehicle, if Carl gets inside it while he's on Fire, or by using a Parachute. To do that, recruit a Grove Gang Member, repeatedly try to get in the Pony by the Driver Doors, your Grove Member will enter the Pony at the Passanger Side.Every GTA SA Save can have 77 Vehicle and Vehicles can be stored in Garages and Impounds. Quickly run to the front as use a Free Aim Weapon to kill him while he's inside the Pony, that will leave the Door open so you can get inside the Pony. Now this is very, very, very important, absolutely make sure that the Mesa spawns with the Roof on. To obtain all three at the same time, start the Ryder Mission Robbing Uncle Sam, get in the Mule and drive to Ocean Docks. The Roof Variant is more of a Prize than the one without the Roof. If the Mesa has a Roof, then climb up the Wall and kill the Weekend Soldiers. The Mesa's Roof is the Secondary Body Color which is conditionaly Visible, it's only Visible if it has the Roof.