This topic has come up from time to time on some of the LH-fan sites...
Only real option is to fabricate a timer circuit based off of a trigger (such as removal of ignition key), that would feed one or more ACC circuits, with a termination based on time or the courtesy lights coming on (door opening).
In other words, there's no short answer, but the solution is doable, with some engineering.
(Dare I mention "Peva" to see if he appears in this thread?

)