So, let's say your friend rips the side door upholstery off his car, brings it to you, and says, can you do this in white?
Of course you can. You'll need:
About one yard of upholstery material
Water-eraseable fabric marker
The original side panel
You will be making two of the piece from the car. Remember to cut one off the front side, and one off the back side.
Lay your original panel out on your upholstery material and pin it down:
Then, trace the panel onto the fabric with your marker. Draw vertical lines about 1/2 inch perpendicular to the panel, and a line connecting them. These will be cut into tabs for an exact replication:
Unpin your original side panel, and cut your fabric on the outisde line:
Then begin cutting the holes out, like so:
Now you have this:
Cut your little lines for the tabs inside the holes:
And around the edges:
Turn the outside edge tabs down toward the middle, one by one, and sew down:
When you hit a corner, make sure the needle is in the fabric, lift the presser foot, tuck the next tab under, put the foot back down, and keep going:
Turn the flaps for the inside holes down to face the outside flaps and sew those down:
When you're done, your back will look like this:
And the front will look like this: (ignore the cat, she's just doing her job)
Thoroughly rinse the marker out with cold water, by hand. Dry the panels on your shower rod, and use spray adhesive to attach them to the car.