Need for speed no limits iOS mechanic level

Hi everyone . I have a problem of understanding what Need For Speed : No limits , iOS version , on my phone , says : 

"Receive 250 mechanic level xp by building this car" 

"Unlock 1 more tuning points by reaching mechanic level 7".

Ok . What's with that tuning points ? (not visual points)

And about that message, is a way to get a car faster ? I don't understand what it means what "mechanic level xp". 

This thing appears only at cars where i have some blue prints but not all of them .