With the V5, you only need to drill one hole - through the plate/wing as shown here:
View attachment 795708
Wires go through the central hole in the L bracket, up and through the hole drilled, and back into the engine (which is hollow/accepts lights with a quick drilling)
For a bottom mount, wires can meet at the bottom - tie all four together:
View attachment 795710
AZIZ! LIGHT!
View attachment 795709
I jut found 19 more decal sheets for studio scale stuff - Lots of options for your X-Wings, gang! REAL silkscreened decals with individual carrier for each decal.
https://www.etsy.com/listing/507430713/studio-scale-star-wars-decals-waterslide?ref=shop_home_active_1