In our Ludum Dare 47 entry Gorilla Taxi you are (this might surprise you) a Gorilla, driving a Taxi.
While creating the game in the short 3 days available for Ludum Dare, i came across the problem of buildings hiding the car you were driving, as can be seen on the right. Obviously, this is not ideal, since the player cannot see where he is driving, and even worse, where other cars might be going.
I found a solution that delivers a perfect result for this game and which you can implement in 60 seconds.
This is an example made in the Godot game engine. But the concepts are simple and apply to most other engines.
On the left you can see the car scene. The car itself is a KinematicBody2D, which contains various nodes, of which the car Sprite is one. All you have to do to solve the i-can't-see-my-car-problem is to duplicate the Sprite and modulate it with an alpha, as seen on the right image. The duplicate should also be raised in the z-index so it is drawn above the occluding elements (the buildings in this example).
To the left rolls the result of this little stunt. When being occluded by a building, the taxi pixel perfectly changes to a "ghost" mode, where you can partially see through the building.
It might seem very rough, but in this case it works perfectly and comes with many benefits:
It would get a more tricky with animations, as the duplicated sprite would need to follow the originals animations. At some point, this will stop being the easiest solution, but you have to judge that for yourself.
If you need this effect quickly, this is the way to go i wager. If you need to see the ground area (aka the street) when being occluded, or have complex animations that are annoying to duplicate, this is not the go to solution (lightmaps probably are). I am sure a lot of magic can be done with shaders, but to my shame, i'm no wizard.
Let me know if you got another solution for it, or if anything is unclear.
PS: If you are looking for a game engine, you have to check out the free, the powerful, the elegant, the amazing https://godotengine.org/