I was just wondering, how do you map ELS to the headlights so they flash on&off with the ELS patten

Copy the headlights, remove all unneeded parts, assign it to a lightemissive material, move them out of the actual headlight so there're no overlap, and attach them to extra5 and 6.

To add to what Cj24 said, your hiarchy for wig-wags needs to be as follows:

extra_5

-extra5

--extra5_L0

--extra5_L1

--extra5_L2

extra_6

-extra6

--extra6_L0

--extra6_L1

--extra6_L2

The extra_5, extra5, extra_6, and extra6 are all dummies whilst the extra5 and 6 _L0, L1, and L2 parts are the actual headlight copies.