I did not install a new aftermarket grille but I did rebuild my grille using a combination of parts from my original grille and a set of cross bars I bought from a fellow Bolter (my original was chrome in poor condition and I preferred painted).
Getting the lights in place between the grille cross bars is challenging as the spacing is pretty tight. To get the mounting studs through the holes the light needs to be tipped in from the rear but the overall height of the light with the studs extending makes the entry angle into the holes cause the studs to grab the hole edges. I slightly larger hole or slot would help.
An access panel would provide options to access the back side of the light but I don't think it would help the light installation problem.
