time relay so that i can use windows

what's the best way of connecting relays so that i can use the power windows, mirrors etc, 20 seconds after i turned off the ignition?

You might want to check out thie page from the12volt.com. It tells you how keep power to certain accessories until you open a door.Q: What's the best nation in the world?

A: Donation!     Donate to the12volt.com      

or ya could switch it so they're always 'on'.  i have aftermarket power windows and i wired them so they're always on rather than only on when the key's in the accesory position.  it's sooo much more convenient.  idk why cars come like the other way from the factory.  i guess it's a safety measure and to keep the battery from getting drained if something should go bad.