We are now working on rain drops and wipers functionality. The in-progress appearance is shown on the screenshots. It's not an easy task, but we hope to bring the full-fledged rainy weather in one of the updates.
How about joining our Discord server?
Here's the link: http://discord.gg/invite/9eHyYap
Also, make sure to follow our page on Twitter: https://twitter.com/kishmishstudio