How do I get more clients in a car washing buisness?

[john]

Hi I'm 17, living in hot old texas. I have been working by myself as a car washer. No, I don't just hand wash and dry. I do interior and exterior cleaning, detailing, armor all, leather. You name it I'll clean it. The problem is I only have a few clients that trust me because I turned their old nasty cars to freshly cleaned cars. I charge 25$ for SUVs and 15-20$ On
Small cars. I am not shy to go around the neighborhood and ask around, but it hasn't been working lately. How can I expand my buisness? I do not want to lower my prices because I do a lot of hard work cleaning. And I already have business cards out and flyers everywhere. Any ideas?