I think this set lacks a lot of functionality, but I have at least added motors and made it remote controlled

It uses a Technic Powered Up Hub and 3 L motors(2 for drive & 1 for steering)

Working steering wheel have been added

I have hidden all electronics(very easy in this big set), very small visible changes have been made

Is there any more functions I should add? There is still one output left on the hub.

Youtube video

Instructions available at Rebrickable

 

Wow! Looks great! Good job incorporating the Powered Up hub into the body without changing it! Where is the hub located?

Between the seats and the trunk, there is a big empty space there.

OK. nice.