I need a graphic designer to help me out with my merchandise.

I have a detailing business and I currently am getting shirts made with the logo on the front although I wanted to add some type of back print as well and I could not make it look to good so I need someone who has experience rather than me. I want it to include the mountains for representation of CO and as well as the city to represent Denver, CO and a nicer/exotic car
with some type of detailing touch such as bubbles, bottle, sprayer, brush, etc. I have attached the main and front logo on the shirts