I'm so sorry. I forgot how to get the slamvan and all I remember is something about doing a mission and before ending or after ending you have to have a friend watch the slamvan?.. I'm just not sure anymore.
You need to own a Casino Penthouse.
You need a working GCTF glitch.
Then you need to do the Ms. Baker freemode job whose name escapes me at the moment.
You also need to get the specific location for the particular job too.
I’m sure I have posted about this before.
Anyhow you do the job solo with your friend in the lobby but not in your CEO/MC.
Once you kill all of the Lost MC stand by a Slamvan until your friend can get there.
You complete the mission and your friend holds on to the car for you while you then setup the GCTF.
You then take the car.
Or
Just try to get someone to help you here.
I have one on Xbox but I’m not sure if there is a working GCTF.
Anyhow you are welcome to PM me if you would like to discuss further.
Oh and here’s a link to my post from a while ago ?