There is a very interesting read on Gas Station Simulator about bonuses and penalties and how they will work across all 3 games in the gas station universe:

https://store.steampowered.com/news/app/1149620/view/3721705159474906459


There is quite a lot of information about Road Diner in particular in there as some of the examples are based on new customer types that will come to Road Diner first. Not to mention the concept of bonuses and penalties from one game crossing into other games in itself is quite fascinating, too. If you played Gas Station Simulator and buy Road Diner once we release it, the time you spent on building up and improving your gas station will directly influence your diner from day 1.

So go and read all about in the link above. And when you are done reading about what the future holds, have a look at the present: we released 2 updates for the Airstrip DLC and another hotfix yesterday so go and check that out:
https://store.steampowered.com/app/2137370/Gas_Station_Simulator__Airstrip_DLC/