Is it ever just "plug and play"?

I think the best solution is to get the wiring diagram from the
spindelberger website, buy a female European connector from your
favorite glider vendor, and wire it up from the lights with separate
amber turn signals and red brake signals. It's a better system, and
means you don't modify your trailer, plus then you can come get me
from a field. This will be plug and play when you get to the port. The
Euro plug has spade connectors, so if you screw up it's easy to fix.
If your car is already wired, you just have to fish out the turn
signals. Most new cars come with a tailer harness plug with all seven
wires (and more) deep in there somewhere, so then you just call the
dealer and get the trailer wire plug.

John Cochrane