It's actually a Glitched Property that can be done anytime. After that you need to exactly know which of those Nebulas are EC Yellow/Green, EC Sandy Brown and EC Red. Just jack them, triple drive them or push them to a Garage to store them or renew them.Every GTA SA Save can have 77 Vehicle and Vehicles can be stored in Garages and Impounds. Sometimes if you weren't quick enough the second EC Nebula might have already blown up.Every Garage in the game has a maximum capacity of 4 Vehicles and every Impound can hold 3 Vehicles. Take note that the EC Red Nebula is Heavy, but that Property doesn't get saved in the Garage. you can obtain the EC Nebulas with the DP/EP/FP/MP NE BF-400, so check 1.7.So be sure to buy all the Safehouses with Garages before proceding with the Special Vehicle Hunting Quest. if you want to know how to do that or just check this Video by rtyuijhghff.
Before starting the mission get a NRG-500 or any fast Bike and drive it staight to the Just Business mission location.While completing the school in general is quite difficult, getting all gold medals is very tough for all players, and most golds are the result of a fluke.Challenging points are time limits, and a damage meter. Video by Lethal Vaccine If you want to obtain the AP Packer, you should do this quest first as it involves playing with the Impound. Make note that this one, like the AP Packer, is not possible on Mobile without a Controller plugged in the device.