I've never had a rear wiper that I haven't had to take a Dremel to. Even when I bought the arm and blade from Land Rover Parts and Spares Direct. Just one of those things.

I had excellent results from just splicing a 1/8 plug into the wires that run to my CD changer. Took a little trial and error, but works like a charm. I now have a 1/8 plug on the passenger side seat control panel and one inside the centre console box that I have a bluetooth attached to. Cost about $2.
Move the seat all the way forward and you can get easy access.
You'll have to leave a (long) CD in the changer and it shuts down for 10 seconds when the disk ends, but no big deal.
I was originally going to put a switch on the splice so I could still use the CD, but it came too late and I realized I don't use CDs anyway.