I'm looking for some good companies to look at for sponsorships anyone have any good ideas?

Go local and be specific in your request, motor, wheels tires etc,  Helpful if they can buy you something for the car like a 5 point seat belt.

Local and close to your school is usually best. Have a binder made up showing pics of your car in races being constructed and in races. Offer to advertise on your car and on your trailer. Students approaching a business in a clean and professional manor is generally very positive, most adults want to see students do things that are positive. Tell them about your wins, if you have not won yet, tell them why you are going to next time. Be positive and humble. Be grateful and polite even if the answer is no. You never know who they might tell about you even if they can not sponsor at the current time.