How do you get someone talented into Nascar?

My son has built a racecar from just a frame, built everything from the rollbars to the engine. He now races at a dirt track in Sycamore, Il., called Sycamore Speedway. His father began racing in Rockford Il. on a clay track. They now both are at Sycamore. My son Cody Brewer ran his first race and took 4th his father took first. I believe with Cody's skill at building his own car he will be in first in no time! So how do you get someone "in"? Even as a mechanic??