Anyone getting custom-fit car covers online with free shipping?

I have been running a small shop in a small town, and importing car accessories online from manufacturers in various regions for several years. Since my market is small, my MOQ is below a hundred. I have no bargaining power for lower the product prices or free shipments from the manufacturers to my shop.

Recently, I am frustrated with rocketing shipping costs, especially for custom-fit car covers. Each custom-fit car cover cost around thirty bucks, but its shipping cost over thirty bucks. I have asked logistic services about costly shipments. They suggested that I can save some shipment costs by shipping all the stuff in one single batch.

However, none of my current suppliers can offer all custom-fit car covers which are different in car brands, models, manufacturing years, configurations and colors. My current suppliers are located far from each other. All of them have refused to offer free shipment to one of them and arrange one single shipment to my shop.

Their refuses make me even more frustrated. Honestly, I want to no longer offer custom-fit car covers once current stock is sold out and no matter I will be losing about a quarter of customers. Maybe, I'm now too frustrated to think about that. Anyone can tell me how I can order custom-fit car covers online and get free shipments?