How do I get a sponsor's attention when my emails and calls aren't being returned?

Be relentless and show up where the people you want to meet will be. Think like a marketer - your first impression represents what you'll do for the brand. Be creative with your approach (sending model cars with race results, unique packages that stand out from hundreds of other requests). Build your public presence through social media and content so brands can research you and see your voice and story before responding. Don't send five emails and give up - keep networking and making yourself known in the right circles. When you do get a callback, be open to what the brand has in mind rather than pushing only your agenda.