Collision detection in angled perspective like NES TMNT2 and Metal Gear

[imacomputertoo]

I'm trying to do collision detection for a game that has a camera perspective similar to NES classics like Metal Gear, Teenage Mutant Ninja Turtles 2, and double dragon. It's mostly top down, but at an angle so that you can see the sides of objects and characters. See the image for an example. Notice how the play sprite (green) can walk all the way up to the car until his feet touch the bottom of the car. So the collision is not on the whole character model, only his feet. Also, when attacking or being attached the player sprite and the enemy sprite must be on the same horizontal plane for their attacks to collide.

I've been trying for ages to get something like this to work in Phaser, but I don't know how. Are there any solutions out there? Any games written in phaser that already do this?