Installing interior carpet

What are talking about here? Race car, show car or both?
It the carpet set the factory style loop with the rubberized backing? (Black)
Or poly backed (transparent to white)?
You can melt the edge to help with the unraveling to some extent but sewing a edge binding
is the correct way that will last.
You must always work the carpet from the center out like a decal to determine the locations for the cuts.
It is a difficult job to try and explain in text.