Let's talk about influence. As an engineer, how do you get it, earn it, wield it, or lose it?
(The answer is NOT "become a manager.". In a well-functioning org, managers have mostly separate sphere of influence. If this is not true of yours, change it or leave.)
When we first started the biz, we wondered, how do you sell to a big corp? How do you get an "in?" Here is a thread on what's worked for us.