Heterogeneous Objects on a Single Tile Map

I want to display different objects on a single tile map. As a quick example, I would like to show population size and number of cars per person on the same map. Note that I need to be able to distinguish visually places with a large number of cars from places with large numbers of people.

Am I stuck having multiple maps on my dashboard?

You are correct, at the moment only single-value tie maps are supported.

It might make sense to submit an enhancement request in Github, if this is an important use case for you: https://github.com/elastic/kibana/issues