You'll find car parts and one car with lights still on. When you've found all parts you'd be able to repair that car and escape and win the game.
Viewing post in Zombies vs. Plants jam comments
Unfortunately after spending quite a while looking around I wasn't able to find what I assume to be the last missing part.
The size of the map makes it quite hard to properly look through the entirety of it along with the walk speed.
Along with the day and night cycle locking you out for a moment preventing you from properly looking around. Another thing was that most of the paths there are seem to lead the player to a seemingly random location or a dead end except for a few.