Momentum Hyundai is your Fairfield, CA Hyundai Dealer. We are also convenient for drivers from Vallejo, Martinez, and Vacaville. Visit our full service dealership for any maintenance service or repair! We are ready to assist you with all of your vehicle needs. Momentum Hyundai is your Fairfield, CA Hyundai Dealer. We are also convenient for drivers from Vallejo, Martinez, and Vacaville. Visit our full service dealership for any maintenance service or repair! We are ready to assist you with all of your vehicle needs.