I have only recently observed that,
while by now we all know the laws deactivate on the end of turn if you can't maintain them and are thus essentially free, (neat mechanic huh?)

you can purposely create such situations on demand by using diplomacy influence costs, which are then returned should the deal go ignored post-law deactivation calculation.

Of course the observation might have been mislead by other ongoing effects. And should be subjected to further testing.

Sample scenario:

I have 2K influence, I run -500 laws with *ongoing effect irrelevant to end turn calculations* such as the +hp and +wep/mp dmg and +dust/science on CP kill laws.

Now I don't wanna spend that 500 influence, so I go to diplomacy screen preferably shortly before turn ends and propose some stupid deal to a player that has ended their turn by now and is possibly not paying attention or too lazy to even press decline costing me 1900 influence. (something among the lines of requesting tons of research etc.)

Turn ends, deal gets autodeclined, laws get autodeactivated and I have all my influence back, spending less than original 500 on maintaining while still achieving the sought after bonus.

Proposed solution:

Return influence from autodeclined deals prior to end turn law calculation.