Hi Claudio,
Rather than modifying/adding to the steering wheel is there another way you could interface with someone?
The design laws Trent mentioned wouldn’t be the only governing rules here either, I imagine Uber would have some strict terms as to what else you are allowed to concentrate on other than the road (like many things if you misuse something it can become deadly - a car is inherently dangerous already).
I’d definitely check out @John74406 's speedo for some idea’s he’s done an excellent job of the whole project: GPS speedo design in the making
PS: any kind of 2.5 GHz wireless radio will use some pretty decent amount of power, most small batteries are physically limited to how much juice can be delivered.
A less intrusive dash mounted system might be the way to go 
