We have two vehicles set up as toads. On both, I added
Maxxima LED Surface MountsOn my pickup truck, I made little aluminum brackets to avoid holes in the body. On wife's Corolla (with her permission) I drilled for stainless steel screws. Those lights, those holes, aren't going to change trade/resale on a 2006 with 100,000+ miles.
Much of my reason why, was the RV wasn't supplying enough current to properly light incandescent bulbs.
Separate Bulbs are good because you have zero worries about involvement with toad's electrical system. They won't look as bright as the OEM lights because the OEM bulbs are in a focused position the additional ones won't have.
I don't know much about Plug'N'Play. I'd guess it connects to OEM wiring and geta diodes in place to isolate toad's system from RV's lighting. If that's what it does, it'll preserve the focus of the OEM lamps.
The deluxe route: Cars sold in Europe get different light assemblies. There's another red light where USA has a reflector. They provide a bright red light aft for running in poor visibility. You can wire them for Stop/Tail/Turn and have independent, focused, lamps.