it would be cool for BeamNG Drive to make a game that we can reconstruct BeamNG Drive cars like Car mechanic simulator or My summer car
I suppose a hands on first person build your car thing would be more fitting for another title than Drive is, but if you want that sort of game then the established titles already work fine. BeamNG.Drive as a project takes a lot of resources as is, creating a second project before finishing the first would just be intensive for a medium sized independent company.
There is literally no point in making another game. This is already the successor of Rigs of Rods, so why make a successor for BeamNG?
You mean successor, right? Back on topic though, they really need to focus on finishing BeamNG.drive before anything else. This game has been in development since at least 2012, and we're about to enter the 2020's and it still hasn't even left Alpha. They can't keep doing this forever, they really need to finish this game, hopefully sooner rather than later.
The BeamNG devs are pretty much pioneers in what they do with this particular game engine, so they have to make everything themselves & can't just quickly look up solutions on how to make certain game mechanics. Obviously, if everything were perfect & this was their next game in a row, then yes, we probably would see the game being fully released much earlier, but as of right now it is an alpha & that doesn't matter much in terms of the sheer complexity & development resources of this game