[oil pan 4]

I am just going to apply them as instructed, just shorter runs of lines and fewer of them and provide my own power source.

Using shorter runs or fewer lines will how no effect on the functionality of the grid its self at all. Problem is the provided power/time controller will not work. If I try to use the provided power/time controller it will fry the grid or its self.

I was not sure how much power to apply. Then I realized they spelled it out very clearly in the technical specifications. For the 83 inch install using all 8 grid lines the books says it should use 16 amps. So I know length, amps and volts that is more information than I need. I end up getting a total power dissipation of 0.3 watts per inch of grid.
With the short install of 68 inches and 20 amps I get 0.44 watts per inch.
So any where between those two watt/inch numbers should be good.

Now I plan to use about 60 inches and 4 grids.
If I want to get 0.3 watts per inch then I will need to limit power to the grids at 6 amps on the low end.
Then on the high end, 0.44 watts per inch I want to limit power to 8.8 amps.
I have a feeling that 6 amps will be plenty.

The other good thing about using half the grids is that gives me more grids to put some where else. But I will have to buy another pair of grid bases. Grid bases are the sticky thing that the grid ends attach to and get their power from, also where you hook up the power.
I am thinking with the other 4 grids I will just run them the down the length of the passenger side rear glass. That way I can see my blind spot when I am in the left lane when its icy or when the window is frosty.