Blynk is an IoT process… not really meant as a basic GUI, although many (like myself) primarily use it as such.
It consists of three sections, The App, The Server and the Hardware Device (AKA MCU) or in your case one of the ESP options (I recommend the ESP8266 to start for such usage). All need to communicate with each other… generally over the Internet, thus wirelessly.
One way you can use Blynk in a mobile scenario will be with a Local Server also installed in the car (typically on a Raspberry Pi which is also running as wireless AP), with both the App and the ESP connecting and communicating to it via WiFi.
Not an easy beginner project.
I recommend you do some simpler benchtop experiments and learning, long before going independently mobile with Blynk