What controller for a radio-controlled car can you recommend?

Question

Do it yourself

The task is as follows: either to purchase a ready-made radio-controlled car or to assemble it in parts on your own. With the ability to control remotely while in a Wi-Fi or 3G coverage area, i.e. driving should be carried out "from anywhere" on the planet. Perhaps there are some ready-made controllers, and do they have an API through which this can be implemented?