I have done that on other cars a couple of times and it came out well. The tricks are:

1. Do not use rubber backed carpet. It will not lay smoothly. Use a jute-backed carpet such as used in your home. Cut an underlayment pad for it if needed.

2. When you cut the carpet, cut from the back side, not the front. That way the edges will not be visible since you will cut only the backing and not the pile. By the way, I did not get my edges bound. Most of the edges end up under interior trim anyway.

Great rainy weekend project.