Cass's Truck...How do i get in?

I have walked all round it and even through it but i can't jump in to drive the thing. Help please!

I just pressed up on the d-pad which summoned another truck next to it then press square to get in... :)

I didn't even think of that, just did it and it worked. Thanks

I just did it kinda by accident lol you're welcome :) check your private messages

That mission was glitched in the beta as well. Also if you do finally make it in you have to make sure you get into the driver seat or else you can't drive. I walked that entire mission in the beta and full game release lol.