You shouldn't be frustrated because our cars weren't designed to handle LED trailer lights. It is a very new technology, especially on trailers.

I went through all the same stuff you did, talked to the etrailer people, talked to local trailer people, the BMW dealer, independent shops and even Featherlite... trust me, all you need is the adapter harness and you'll be good to go.

For $25, it doesn't really get any easier.

__________________
12 X5 M - 06 X5 4.8iS - 03 X5 4.4i - 03 M5 - 02 X5 4.6is - 99 M3 Dinan S3 - 98 M3 - 92 850i-6 - 92 850i - 91 325ix - 89 M3 2.5 - and a few parts cars