IMO

Its rediculous to get 20 all around or 35 in front and 5 in back, or anything illegal and expect to get away with it.

Cops know whats illegal, and all it takes is a simple slide of the meter to prove it, no matter what window it is. Why do it half a$$ed like that? Do you really believe you are "fooling" them?
Those that have anything illegal have just been lucky, nothing more. Eventually luck runs out.

You have two choices:

1) Get what you want, but be prepared to get fined and have to pay to have it removed.

2) Get the darkest allowed by law and forget about it.