ok everytime you exit the truck (it says enter truck, but i know it's exit) you have to make sure to look away from the beacon on top of the truck, and while trying to move forward you hit ctrl for crouch. that's the only way to get passed it that i've found. it took me a very long time to figure out i needed to fix the engine, because i cant really understand the characters dialog lol. then when i fixed it i tried to get back into the cab and it i guess something knocked me away from the truck? i just started flying very fast away from the truck and i ended up just walking around in some blackness forever lol.
anyways i write this so you can look into it if you wanted to. cool idea, but those bugs make it extremely difficult to get to an ending. good luck on your next project tho! :)