Adding Delay to ACC.

I'm about to rewire my car and was wondering if anyone had ideas or knew how cars add a delay to power for radio, interior light etc... in the wiring ?
I will adding this device from Amazon to my lighting.
Amazon.com: Small Miniature time on off cycling delay relay 0.1 sec to 9999 hours. 5V 12V 18V DC 5A. Power On Off delay, Cycling. Industrial control and hobby: Home Improvement