EDIT; Ugh f*ck me, caught by the Necropost. What the hell is wrong with people today, Necroposting like there's no tomorrow.
It is preferable to flooding the forum with the same topic over and over.
I've been trying to store one from stocks and scares with out any luck. Why would rockstar even bother stopping you having this vehicle. I regret getting rid of my last one before they stopped you owning one. I'll give that gang attack a go.
Try storing one from calling the Mercs on someone, that might work.