Hello, good I would like to take a doubt. well i have punto 2008, i would like to put a screen with realdash, well i know i can do one of the integrations with obd2, via bluetooth. but only with some information. but I would like to add more information. such as arrow, flashes alert, fuel level and other information. I’m new, I don’t know much about programming. but I would like to know about another integration that would be about realdash can, and how is the connection made with arduino? and what components to use? . connection can act with ELM327 simultaneously on the vehicle’s obd2 input? using an adapter? and how would this connection be made? I hope I can help myself, I look forward to putting it into practice. 
You can try the direct CAN connection to your vehicle thru OBD2 port, and use the CAN Monitor to see what data is running in CAN bus. Then you would need to analyze the data and write a XML file that describes how CAN frames are interpreted by RealDash.
It can be done, but is a lot of work. But it can also be quite fun and educational. Unfortunately we are unable to remotely help you with this procedure, as it would take hours, if not days to complete.