timer relay with constant trigger

I want to trigger a timer relay (approx 5 seconds) with a constant 12V source. No alarm system is installed.

I want the park lights to go on for a few seconds and/or flash a couple times after 12v is supplied to a relay...problem is my 12v source will remain constant after the park lights go out.

Will the 528T work? It appears it only takes a pulse input.

Any suggestions on how to do this?

528t will work.  It doesn't matter if the input is pulsed or constant. Of course you could feed it from the ign wire, that goes to ground when you turn off the engine,  join this via a diode, band towards ign wire to the black 85,then constant fused input on the 30 yellow  and 86 trigger wires, brown 87  will then feed 12v+ to the relevant light wires (assuming pos feed) for the time you set it. If a neg output is required, simply join the red 86 to a constant 1amp fused 12v+, 87 as before, 30 to ground, 87 to light feeds. In both cases ignore 87a orange wire.