I did - when I was using the factory unit with the Drive+Play. I had to get from the antenna to the Drive+PLay, then from the Drive+Play to the Head Unit. But that was because the Drive+PLay was U.S. antenna connectors (one male, one female).

I would think you'd just need one. Maybe you have two different ones each only has one correct end on it.

When I put in my Pioneer, I just needed one - from the antenna Euro, to the head unit U.S.

Not sure any of this really helps you though...