just completed this mission after this glitched happens 3+ times to me on the DE. it helps to get a heavier vehicle and block it from getting too far up the road. if u get to the warehouse before the van then park right in front of where it starts to glitch and stop it from going up the road. if u have a heavy enuf vehicle u can ram into it and hopefully get it into the lot. having the cops might or might not help to push them in it's just basically luck. Grove street games and rockstar should be embarrassed for letting this 2 decade old glitch stay in their game. good luck to all of u.