How can I convince a small time car showroom owner to buy Digital Signage system from me?

I am trying to set up a business by selling digital signage solutions. To grow I need to sell my products to small time business owners. I have an appointment with a small time car dealer who owns a car showroom. The person seemed not much interested and unlikely to purchase the solution from me so is how can I convince him to buy the signage soln from me. Any taglines or any marketing strategy.

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digital signage san jose