Custom T-Shirt Design Script

Normally this program uses a 3D image of a t-shirt to write onto so the client can view a virtual t-shirt with his custom uploaded art on it and see where it fits on the t-shirt. The only difference for me is that my 3D object is the canvas of a Kombi poptop. This is where they can custom design what they want printed onto the polysester canvas which is of billboard quality. I need that feature on my website. It is then rendered onto the 3D Kombi w. Poptop so they can see what it will look like. They then Checkout and buy the print. I cut the 3x2 meter length from my roll, print it, then cut the canvas up with the template and stitch it together to make the canvas annex hood for the poptop. Then I mail it to them... They go install it on thier Kombi camper and there you go all their art/imagery on the canvas looks just like it did on the virtual 3D Kombi camper. So, essentially its no different to a custom t-shirt just that the 3D image surface is a annex hood for a Kombi camper.