This is an intern-style career if I ever saw it.
In the old days, you had to get into the HR office to get considered.
I see a road trip to LA or New York as mandatory.
You'd have to guess that there are forums where the insiders hang out, but I'd have to search. Find an employee or past consultant from the company you want to interview with. More than almost any other profession, this has got to be a Who ya know, not What you know, business.