The glider isn't always plug-and-play, so we shouldn't expect the
trailer to be either!
Starting with a tow vehicle that has tail lighting of the modern
international standard, not the 1950s 4-wire system illegal in most of
the world, makes the job easier. US auto manufacturers only stay with
the ancient way because it involves less wire. Intentionally having
only one working brake light while turning is a strange concept.
Then decide which "large connector" you'd like on both. The US 7-pin
is quite common, but ones installed at the dealer seem to get wired as
a 4-wire system and most are plastic. I use the 6-pin round "redondo
de 6 polos", which has a metal chassis but unfortunately comes without
the 6 chickens.
With the extra pin(s) you can hook up reversing lights or interior
lights.
Build adapters to and from everything you can imagine, then perhaps
add adapters to bare ends, spade connectors or alligator clips, and a
roll of electrical tape to your kit. Keep the appropriate set in the
tow vehicle and the other set in the trailer.
If you make the adapter from your vehicle to European round,
electrically it'll be plug and play at the docks.
As mentioned before, LED lights are the way to go. Couldn't find
them in the US due to the abundance of stone age trailer lighting. The
most convenient place I found red/amber LED lights was ebay in
Australia. The same LED lights are available at many parts suppliers
there, but they may not ship overseas. The square ones I have are a
couple of mm smaller than the round hole in a Cobra trailer, so some
home made parts are needed to cover the edge of the holes up. An
example of the lights and cost:
http://cgi.ebay.com.au/2-x-LED-STOP-...7 C240%3A1318
Of course you can find "buy now" ones too.
Jim