I tried once more to make a decent looking wheel cover using vinyl sign lettering material. This time I went on line to Sign Warehouse Inc and found some thicker black vinyl that is 3 mil, almost twice the thickness of my first try. The part number was VEG-500-2410-502 and came in a roll 24 inch by 30 f00t for $18.59 plus $10.18 for shipping. This is enough to make 4 or 5 four wheel sets of covers.
Below are some pictures of how I made them.
First I made a pattern on the back of the vinyl peel off portion. These dimensions will cover all the "holes" on a 14 inch Insight space saver wheel.
Here is the "donut" cut from the roll.
Then I cut across the "donut" so it would lay flat on the cone shape of the wheel
I then peeled off the backer and wet the wheel surface and the back of the vinyl donut with some soapy water, This made it easy to place the donut where I wanted it and remove any wrinkles or bubbles.
Here is a picture after it dried. You can still see where the "holes" are but I think it is still acceptable as a cheap and very lightweight aero wheel cover.